Mikkipedia

Mikki Williden
  • 5.0 (21)
  • Health & Fitness
  • Updated Weekly

Mikkipedia is an exploration in all things health, well being, fitness, food and nutrition. I sit down with scientists, doctors, professors, practitioners and people who have a wealth of experience and have a conversation that takes a deep dive into their area of expertise. I love translating science into a language that people understand, so while some of the conversations will be pretty in-depth, you will come away with some practical tips that can be instigated into your everyday life. I hope you enjoy the show!

  1. 1d ago

    Carbohydrate Per Hour in Ultra Running: 90 vs 120 Grams with Paul Booth

    Save 20% on all Nuzest Products WORLDWIDE with the code MIKKIPEDIA at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.com Episode Summary Paul Booth, sports nutritionist, exercise physiologist and PhD researcher in ultra-running metabolism, is back on Mikkipedia, straight from UTMB week in Chamonix, where he raced OCC and worked with elite athletes. Mikki and Paul pick up where they left off a year ago, talking about how much carbohydrate trail and ultra runners actually need. Paul shares results from his own blinded field study comparing 90 g and 120 g of carbohydrate an hour over 55 km. It found no difference in total time, climbing or descending, but every runner had more gut distress on 120 g after about four hours. They also cover how Paul builds race plans from lab testing, training files and years of race split times, and why he thinks faster ultra times owe more to better training environments than to race-day fuelling. He explains the everyday gaps he sees most (refuelling after training, protein at breakfast and meeting total energy needs), and why age-group runners may do well starting nearer 60 g an hour and building only if they need to. Paul is careful to say his findings apply to trail and ultra running up to the distances he has tested, not to cycling or triathlon. Key Topics Paul's OCC race: just over 11 hours on a hot day, fuelled at about 60 g of carbohydrate an hour, completing his set of UTMB ultra racesCaffeine at the elite end, including a CCC podium athlete who took far more caffeine than planned while racing through a knee injuryLab testing in heat and altitude chambers to find each athlete's gut ceiling, and using race modelling to find where carbohydrate can come down as well as upWhy Paul thinks faster ultra performances are driven mainly by more professional, strategic training, and why over-fuelling on race day adds nothing but gut issuesThe risk of pairing very high in-training carbohydrate with "burgers and pizza" to meet energy needs, when fruit, vegetables, fibre, iron and micronutrients still matterThe most common everyday gaps: delayed refuelling after training, too little protein at breakfast, and under-eating total energy on high-volume daysWhether 120 g an hour is justified: Paul sees elite intakes settling around 100 g, and reported high intakes are often overstated once discarded gels and bottles are countedPaul's 90 vs 120 g field study: no significant difference in time, climbing or descending, with a consistent rise in upper-GI distress on 120 g after about four hoursPractical advice for age-groupers: start around 60 g an hour, build towards 90 g only if you are comfortable and racing hardGlucose to fructose ratios: why 1:0.8 mainly matters above about 90 g an hour, and how sponsor products shape what athletes can takeChapters 00:00 Introduction04:02 Paul's OCC race at UTMB week07:32 Elite race results and caffeine plans11:52 Lab testing and race modelling21:47 Why ultra times are getting faster26:47 Training fuel versus overall diet quality32:04 Timing, recovery and breakfast protein34:27 Is 120 grams an hour justified?41:52 The 90 vs 120 gram field study53:55 Fuelling advice for age-group runners56:29 Carbohydrate intake and recovery1:00:05 The 10 grams an hour argument1:05:00 Glucose to fructose ratios1:08:56 Paul's podcast and how to reach him Guest / Resources Paul Booth on Instagram: @ultra.endurance.nutritionistPaul's website, Performance Gains: performancegains.co.ukPaul's previous Mikkipedia episode (398): Fueling Tom Evans and Ruth Croft's Victories at UTMB: Inside Elite Ultra Nutrition with Paul BoothPlews DJ, Booth PD, Krieger T, Maunder E. Fuelled or Fooled? Examining the Evidence and Mechanisms Behind Ultra-High Carbohydrate Intake in Endurance Athletes. Sports Medicine, 2026Paul's 90 vs 120 g per hour field study in ultra runners, presented at the ECSS conference (not yet published)O'Brien WJ, Rowlands DS. Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance. American Journal of Physiology: Gastrointestinal and Liver Physiology, 2011. The origin of the 1:0.8 ratio discussedMNSTRY's podcast, which Paul co-hosts: mnstry.podbean.comAthletes and people mentioned: Tom Evans, Ruth Croft, Miao Yao, Gemma Hillier-Moses, Rachel Entrekin, Dan Green, Dr Dan Plews, Tim Podlogar, Alistair Brownlee Curranz Supplement: Use code MIKKIPEDIA to get 20% off your first order - go to www.curranz.co.nz  or www.curranz.co.uk to order yours NZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nz Contact Mikki:https://mikkiwilliden.com/https://www.facebook.com/mikkiwillidennutritionhttps://www.instagram.com/mikkiwilliden/https://linktr.ee/mikkiwilliden

  2. 3d ago

    What 99% Accurate Really Means on a Body Composition Scale

    Episode Summary A client sent Mikki a link to a very flash Withings bioelectrical impedance scale — NZ$819, marketed as 99% as accurate as a DEXA scan — and asked the obvious question: is it worth the money? In this solo episode Mikki goes and reads the validation document behind that claim, and finds the problem isn't really the scale at all. It's a statistical sleight of hand that turns up constantly in health tech marketing: reporting a correlation and calling it accuracy. Mikki explains the difference in plain terms, with a worked example where a scale reads exactly half the true value every single time and still produces a perfect correlation of 1.0. She then sets the company's own document against three pieces of independent research — a January 2026 systematic review of BIA against a four-compartment model, Siedler and colleagues' 2023 comparison of fifteen BIA devices, and a June 2026 study putting the InBody H20N up against DEXA — to show what honest reporting of a body composition device actually looks like. She finishes with the four readouts on these scales that aren't worth your attention, a practical protocol for getting genuine information out of the one you already own, and four questions worth asking of any health tech accuracy claim you meet in the next few years. Key Topics Correlation is not accuracy. The 99% claim rests on a correlation of 0.99 for total fat mass across 80 people. Mikki accepts the correlation is real, and shows with a worked example why it says nothing about whether any individual reading is right.What you actually want is agreement. Mean difference and limits of agreement, via a Bland-Altman analysis — the standard approach since the mid-1980s, and one the company's document didn't use.What the validation document left out: mean difference from DEXA, limits of agreement, individual prediction error, the age and sex breakdown, the body fat range, whether hydration and fasting were standardised, and whether the validation sample was independent of the data used to build the algorithm. Mikki could find no peer-reviewed publication of it, and notes total body water was validated against a different device entirely.Better hardware doesn't settle the evidence question. Mikki is clear the Withings unit is well built — eight electrodes including a handheld bar, multiple frequencies, current through arms, trunk and legs rather than up one leg and down the other. That is a separate question from whether the accuracy claim stands up.The independent evidence. A January 2026 systematic review of 12 studies found mean bias for body fat percentage ranging from 3.5 percentage points too low to 4.4 too high, with limits of agreement typically spanning 15 to 20 percentage points, and concluded BIA was not equivalent to the four-compartment reference.Reliable does not mean accurate. Across 15 devices, precision error was 0 to 0.5 percentage points — these scales are very consistent with themselves. A device can be reliably wrong, which is why direction of change can still be informative even when the absolute number isn't. The longitudinal results were more mixed: some devices tracked change reasonably, others didn't.What honest reporting looks like. In 55 adults with obesity, the InBody H20N sat 1.64 percentage points from DEXA on body fat, with limits of agreement of −3.4 to +6.7 — good across a group, much looser for the individual standing on it. Skeletal muscle mass was worse, overestimated by 5.66 kg on average. Less impressive than 99%, and far more useful.Four readouts not worth watching: visceral fat (a proprietary index on an arbitrary scale, not a measurement of visceral adipose tissue like CT or MRI); bone mass (not bone mineral density, and no guide to osteoporosis risk — DEXA is the answer there); basal metabolic rate (calculated from an equation, not measured — that needs indirect calorimetry); and body water (better on a multi-frequency device, still modelled).How to use the scale you have. Standardise everything you can control, because hydration, glycogen and cycle phase move these numbers more than real change does over a short window. Measure three or four times a week, average weekly, read four-week trends, and triangulate against weight, waist, clothing fit, training numbers and photos. Swap "my body fat is 23.7%" for "my body fat estimate has trended down over the last 10 weeks".The transferable point. InBody's own product page claims over 98% agreement with DEXA — near enough the same move. When you're told a number is 99% accurate, ask what that means, what it was compared against, who paid for the comparison, and how far off an individual reading can be.Chapters 00:00 The $819 scale and the 99% claim02:15 Why correlation is not accuracy04:27 Better hardware, missing evidence06:48 What the independent research shows09:10 InBody versus DEXA: the real numbers11:53 Readouts not worth watching13:27 How to use a scale well15:40 Questions to ask of health tech Guest / Resources This is a solo episode — no guest. Studies discussed The Validity of Bioelectrical Impedance Analysis Compared to a Four-Compartment Model in Healthy Adults: A Systematic Review — Journal of Functional Morphology and Kinesiology, 31 January 2026. Twelve studies; mean bias for body fat percentage −3.5 to +4.4 percentage points; limits of agreement typically 15–20 percentage points. https://doi.org/10.3390/jfmk11010065Siedler MR et al. Assessing the reliability and cross-sectional and longitudinal validity of fifteen bioelectrical impedance analysis devices — British Journal of Nutrition, 2023;130:827–840. Seventy-three adults across 15 BIA devices against a four-compartment model, with 37 returning 12–16 weeks later for the longitudinal analysis.Ellison KM, Gard W, Wood J, Layton C, Sayer RD. Assessing Body Composition for Resource-Limited Settings: Agreement of a Scalable BIA Device Compared to DXA and Clinical BIA in Adults With Obesity — Journal of Primary Care and Community Health, 2026. The InBody H20N against DEXA in 55 adults with obesity (mean age 62.6, 67% female), under an 8-hour fast with no alcohol or vigorous exercise for 24 hours. The research group is at the University of Alabama at Birmingham. https://doi.org/10.1177/21501319261459756Methods and terms mentioned Bland-Altman analysis — the standard method for comparing two measurement techniques, giving mean difference and limits of agreementFour-compartment model — a stronger reference than DEXA alone, accounting for body volume, total body water, bone mineral and body mass separatelyDEXA — the reference method throughout, and the gold standard for bone mineral densityIndirect calorimetry — what measuring basal metabolic rate actually requires, using a mask and a metabolic cartCT and MRI — what an actual measurement of visceral adipose tissue requiresDevices mentioned Withings bioelectrical impedance scale — the NZ$819 device that prompted the episodeInBody H20N — the consumer-grade portable device in the June 2026 study, AU$529, with no New Zealand retailer found at the time of recordingRelated Mikkipedia episode Prof Gr...

  3. Sep 29

    No Healthy Dose of Alcohol, But Is There a Safe One? With Cliff Harvey

    Save 20% on all Nuzest Products WORLDWIDE with the code MIKKIPEDIA at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.comCurranz Supplement: Use code MIKKIPEDIA to get 20% off your first order - go to www.curranz.co.nz  or www.curranz.co.uk to order yours NZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nz Episode Summary Cliff Harvey PhD is back on the podcast, and this one ranges widely before settling on its main subject. Cliff is a registered clinical nutritionist, qualified naturopath and strength and nutrition coach who has been in clinical practice since the late 1990s, and he founded the Holistic Performance Institute. He and Mikki open with wearables — Cliff has swapped an ageing Oura ring for an under-mattress Withings sleep analyser — before getting into whether an already-active person really needs dedicated cardio, and why Mikki has deliberately upped her carbohydrate intake for running after years of being firmly in the low-carb camp. The second half is a careful working-through of the alcohol evidence. Cliff's central point is a distinction that often gets lost: the research supports the claim that there is no healthy dose of alcohol, but that is not the same as showing there is no safe dose. He walks through why all-cause mortality is the endpoint to start from, where the cancer data genuinely does look different, and why effect sizes at low intakes are small enough to be hard to interpret. Both are clear that alcohol is a toxin and neither is advocating that anyone start drinking. What they are arguing is that absolutist public health messaging that outruns the data erodes trust, and that time spent getting people active would do more good than telling them to drink nothing at all. Key Topics Cliff's move from an ageing Oura ring to a Withings under-mattress sleep analyser, what resting heart rate and HRV are and aren't useful for, and Mikki's 59-day Garmin step streak and how it endedThe one thing they openly disagree on: Cliff argues accumulated movement at varying intensities can make structured zone two largely redundant for an already-active person, while Mikki champions aerobic work in its own right and pushes back on messaging that walking plus lifting is all anyone needsWhy Mikki has substantially increased her carbohydrate intake around running after years of being low carb, and the difference she reports in running, recovery and appetiteCliff on the research he co-authored — habitually low-carb athletes benefit from carbohydrate during exercise to essentially the same extent as high-carb athletes — and early-2000s field research at a 24-hour mountain bike event where athletes needed far more per hour than the then-accepted 60 g glucose and 90 g glucose-fructose ceilingsThe distinction the episode turns on: no healthy dose of alcohol is not the same claim as no safe dose, and why the Zhao 2023 meta-analysis is often read as saying the secondWhere the cancer data does look different, how relative risk and absolute risk come apart, and why a 5% relative increase can mean very little in absolute termsConfounding, residual confounding and abstainer bias — why abstainers can look worse in the data until you account for who stops drinking and whyGuardrails rather than prohibition: Cliff's dozen beers a month, what he used to tell clients, and why zero-tolerance messaging that diverges from the data erodes trust and tends to fail in clinical practiceCongeners, drink type and individual response, including why some people react differently to whiskey than to vodka — and why no spirit gets you out of a hangover at doseLinchpin behaviours: why both land on physical activity as the thing most worth people's limited attention, and Cliff's case for mindfulness as an effective non-diet interventionChapters 00:00 Introduction03:07 Wearables, sleep tracking and step streaks10:38 Does everyone need dedicated cardio15:40 Running, mobility and upping carbohydrate18:31 Carbohydrate during exercise and low-carb dogma28:45 Alcohol guardrails and personal limits33:10 Mortality versus single disease endpoints38:51 Cancer risk, relative and absolute47:29 Confounding, abstainer bias and patterns58:46 Drinking culture and absolutist advice1:07:43 Drink type, congeners and sleep1:13:35 Linchpin behaviours and what matters most1:18:19 Take-homes, recommendations and outro Guest / Resources Cliff Harvey PhD Website: cliffharvey.comHolistic Performance Institute: holisticperformance.instituteInstagram: @cliffdoggydogCliff is a registered clinical nutritionist, a qualified naturopath, and holds a diploma in fitness training and health coaching in patient care. He has over 20 years' experience as a strength and nutrition coach and has been in clinical practice since the late 1990s. His PhD research was in ketosis and ketogenesis, and Mikki helped supervise part of that pathway. In the episode he mentions that a full review on alcohol and mortality was due to go up in the Holistic Performance Institute's database of living review articles. Studies and research discussed Zhao et al. (2023), Association Between Daily Alcohol Intake and Risk of All-Cause Mortality: A Systematic Review and Meta-analyses, JAMA Network Open. The meta-analysis at the centre of the conversation, drawing on 107 studies. Cliff's reading is that it shows no healthy dose, but does not establish that there is no safe dose.Health effects associated with alcohol consumption: a Burden of Proof study, Nature Health (2026). Referenced as looking at disease risk rather than mortality.Sarich et al. (2026), Alcohol-attributable cancer risk and burden estimates for Australia's updated alcohol consumption guidelines, British Journal of Cancer. This is the paper Mikki reads figures from during the episode. It reports that for every additional ten drinks per week, the risk of all cancers combined increased by 5%.The 45 and Up Study — the large Australian cohort (over 225,000 participants) that the above cancer analysis draws on, and the source of the absolute risk figures Mikki looks up live.Mendelian randomisation research on alcohol and risk, referred to in general terms rather than as a specific named study.Research on abstainer bias, which Cliff attributes to earlier work by Zhao and colleagues preceding their 2023 meta-analysis.Zinn, Harvey et al. (2023), Exercise and sports performance, a chapter in Ketogenic: The Science of Therapeutic Carbohydrate Restriction in Human Health (Elsevier). The chapter Cliff co-wrote with Caryn Zinn, and the source of his point about low-carb athletes benefiting from carbohydrate during exercise.Cliff also refers to research on Mediterranean diet and drinking patterns, on physical activity as protective against alcohol-related mortality risk, and on mindfulness as a non-diet intervention. These were discussed in general terms and no specific papers were named.People mentioned Dr Eric Helms — teaches on the Holistic Performance Institute ...

  4. Sep 27

    I Was Wrong About Why Carbs at Dinner Help You Sleep

    Episode Summary Mikki has said many times — on this podcast, on other podcasts, and repeatedly on Instagram — that eating carbohydrate at dinner helps calm the nervous system, and that this is why people who feel wired at night sleep better when they add some back in. In this episode she corrects herself. Not on the advice, which she still gives and still sees work, but on the mechanism she has been attaching to it: insulin clearing branched-chain amino acids out of the bloodstream, tryptophan winning the competition at the blood-brain barrier, and the resulting serotonin and melatonin sedating you. Every step in that chain is real biochemistry, which is exactly why it sounds right. It just does not happen at the doses found in any meal she would actually recommend. From there she works through what is more likely going on. She covers the head-to-head trial that put carbohydrate, two proteins and a placebo up against each other before bed and found nothing; why the pre-sleep protein literature is muscle research rather than sleep research; the difference between an energy deficit and low energy availability; and the body of work on cognitive dietary restraint — the mental effort of not eating, which carries measurable physiological consequences independent of how much is actually eaten. She is careful throughout about how messy cortisol data is, and about which parts of it she thinks still stand. The practical conclusion is unchanged but better founded: if you are wired and under-eating relative to your training, it is probably the calories, and carbohydrate is usually the easiest thing to add back. Key Topics Why the mechanism matters even when the advice is fine — Mikki's argument is that people do not just follow advice, they extend it using the mechanism you gave them, so an explanation that isn't real can cause problems in situations you never had in mind.The tryptophan pathway, and where it breaks — the effect requires carbohydrate high enough and protein low enough for tryptophan to win the competition at the blood-brain barrier. Add meaningful protein and it disappears, and the melatonin generated downstream is nowhere near a dose that influences sleep.Lower carbohydrate was associated with more slow-wave sleep, not less — a meta-analysis of polysomnography studies found lower carbohydrate intake linked to more slow-wave sleep, less REM and a shorter time to fall asleep. That is the opposite direction to what Mikki had been saying.The head-to-head trial in elite female athletes — 40 g of alpha-lactalbumin, 40 g of casein, 40 g of carbohydrate or a non-caloric placebo, taken 30 minutes before bed for three nights each. No difference in total sleep time, sleep onset latency, subjective sleep quality, resting heart rate or heart rate variability, and no difference in overnight glucose on CGM.Pre-sleep protein is muscle research, not sleep research — protein before bed does do what it says for the overnight muscle protein synthetic response. That is a separate question from whether it sedates you, and when sleep is the outcome tested directly it is no better than carbohydrate or nothing.Why it still works in clinic: it is the calories — the null trial was run in adequately-fed people. Mikki's clinical population is in a deficit and often training hard, so adding food at dinner adds total energy to the day. Carbohydrate is simply the lever she usually reaches for, because protein is normally already handled in a fat-loss meal.Energy deficit is not the same thing as low energy availability — two women in the same deficit can be in very different positions depending on training volume. Mikki cites the 30 kcal/kg fat-free mass threshold and is explicit that it is not a number everyone agrees on.Cognitive dietary restraint has physiological consequences — over two years in 123 healthy young women, higher restraint was associated with more cycles showing subclinical ovulatory disturbances (56% versus 34%), and physical activity, general stress, BMI and energy intake did not explain the difference. Related work found higher 24-hour urinary cortisol in high-restraint women, replicated in postmenopausal women aged 49 to 75.A one-off cortisol test tells you very little — within-person variability is large, the cortisol awakening response has test-retest reliability too poor for individual comparisons, and the research Mikki is drawing on compared groups using 24-hour urinary collections rather than single spot samples. Noise that swamps one person averages out across sixty or a hundred.What to actually do — if you are wired, under-eating and training, add the calories back. Put a small portion of carbohydrate on a plate whose protein is already covered; if protein is the thing that is low, add protein instead, particularly through midlife. And if fear of evening carbohydrate is the real barrier, add it back and watch what happens — evidence builds confidence.Chapters 00:00 Where I got the mechanism wrong02:59 Benton, dose and the sleep studies04:49 Carbs, casein or placebo before bed07:12 Why it still works in clinic08:56 Energy deficit, training load and cortisol11:39 Fear of carbs and dietary restraint14:19 How reliable is cortisol testing16:09 What to actually do Guest / Resources This is a solo episode. No guest. Researchers and work referred to in the episode David Benton and colleagues, Swansea University — work evaluating the putative mechanisms linking carbohydrate to sleep, and a meta-analysis of polysomnography studies finding lower carbohydrate intake associated with more slow-wave sleep, less REM sleep and shorter sleep onset latency.Andrew Huberman — Mikki recalls hearing him make the starchy-carbohydrate-and-serotonin case for sleep. She refers to this from memory; no specific episode is identified.Zach Bitter — mentioned as a low-carbohydrate proponent who reported that higher carbohydrate intake worsened his sleep. An individual account, not a study.Luc van Loon's group — including Jorn Trommelen and Tim Snijders — the pre-sleep protein and overnight muscle protein synthesis research. Mikki's point is that this body of work is about muscle, not sleep.Anne Loucks — the work establishing that luteinising hormone pulsatility is disrupted below roughly 30 kcal per kg of fat-free mass per day, after subtracting the energy cost of exercise. Mikki notes in the episode that this threshold is not universally agreed.Yuko Nakamura and colleagues — a meta-analysis separating the severity of energy restriction, finding that fasting raises cortisol strongly while low-calorie and very-low-calorie diets do not, and that the effect fades over several weeks.Jennifer Bedford and colleagues — a two-year study of 123 healthy young women, finding higher cognitive dietary restraint associated with more cycles showing subclinical ovulatory disturbances (56% versus 34%), with physical activity, general stress, BMI and energy intake failing to explain the difference.Judy McLean and colleagues — 24-hour urinary cortisol excretion compared in premenopausal women with high versus low dietary restraint scores, matched for age, BMI and cycle length.Candice Rideout and colleagues — the same finding in postmenopausal women aged 49 to 75, who d...

  5. Sep 22

    Brandon DaCruz returns: Refeeds and Diet Breaks: What the Research Shows and How to Use Them

    Save 20% on all Nuzest Products WORLDWIDE with the code MIKKIPEDIA at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.com Episode Summary In the latest episode of our collaboration with the Chasing Clarity Health and Fitness Podcast, Mikki is joined again by online nutrition and physique coach Brandon DaCruz to talk refeeds and diet breaks. These tools have been used in bodybuilding and physique coaching for decades, with plenty of claims attached: that they boost leptin, prevent metabolic adaptation or speed up fat loss. Mikki and Brandon start with definitions. A refeed is a structured, tracked one to three days at around maintenance, with the extra calories coming mostly from carbohydrate. A diet break is one to two weeks at maintenance. Neither is a cheat meal. They then look at why a long deficit gets harder over time, through rising hunger, falling NEAT, poorer training and accumulated diet fatigue. Brandon works through the research by outcome. When the overall deficit is matched, the trials and a recent meta-analysis show similar fat loss with intermittent and continuous dieting, and any hormonal lift from a short refeed is likely to be temporary. There may be a small benefit for resting metabolic rate and lean mass, with caveats, and the most consistent benefit is for hunger, dietary satisfaction and adherence. Mikki explains how she schedules refeeds in Mondays Matter as practice at eating at maintenance, and how she plans diet breaks around holidays and busy periods. Brandon walks through how he titrates refeeds with lifestyle and physique clients, and why the extra calories come from familiar carbohydrate foods rather than hyperpalatable ones. Both are clear that these strategies can backfire for some people, and that someone who is progressing well doesn't need another intervention. Key Topics Refeeds, diet breaks and cheat meals are not the same thing. Refeeds and diet breaks are planned and tracked; a cheat meal removes the structure, and both hosts would happily retire the word "cheat" (06:53).Why a prolonged deficit gets harder. Hunger and appetite rise, NEAT drops without people noticing, lower carbohydrate availability affects training, and diet fatigue builds. Brandon likens a refeed or diet break to a training deload (12:46).Refeeds as a skill, not just a physiological tool. Mikki builds three-day refeeds into Mondays Matter every two weeks so people can practise eating more without fear, and both hosts plan diet breaks around holidays and work travel (20:21).Fat loss research. With deficits equated, intermittent and continuous dieting produce similar fat loss. Brandon explains the "whoosh" effect he has seen in practice and why a short-term hormonal boost is unlikely to drive fat loss on its own (28:38).Lean mass, metabolic rate and adherence. There is some signal for better lean mass retention and a slightly smaller drop in resting metabolic rate, with caveats. The clearest benefits are less hunger, more satisfaction and less disinhibition (36:12).Personality matters. Some people will adhere regardless, and for some "abstainers" a single refeed day can turn into an overfeeding week (39:41).Training performance. A carbohydrate-based diet break improved lower-body muscular endurance in one secondary analysis, and Brandon times refeeds around priority sessions for his physique athletes (44:23).How they each structure refeeds. Mikki first rules out non-deficit causes of poor sleep, cravings or low energy. Brandon starts with one day, keeps the usual foods, increases carbohydrate, holds fat and adjusts based on biofeedback (47:46, 50:44).Why carbs go up, not fat. Fat is usually already low deep into a diet, protein often has a buffer, and food volume matters: energy-dense "refeeds" can leave people eating less food and feeling hungrier (59:58).Who benefits most. Long-term dieters who are getting leaner than ever, training hard and struggling with hunger or fatigue. For someone losing at a good rate and adhering well, adding one can simply break momentum (1:13:17).Chapters 00:00 Introduction and the collaboration series06:53 Refeeds, diet breaks and cheat meals defined12:46 The costs of a prolonged deficit20:21 How Mikki uses refeeds with groups and travel28:38 Do refeeds improve fat loss?36:12 Lean mass, adherence and personality types44:23 Refeeds and training performance47:46 Mikki's one-on-one approach50:44 How Brandon structures refeeds and diet breaks59:58 Why carbs go up, not fat, on refeed days1:07:28 Benefits seen in practice1:13:17 Who benefits most, and wrap-up Guest / Resources Brandon DaCruz, online nutrition and physique coach, accredited nutritionist and host of the Chasing Clarity Health and Fitness Podcast. Instagram: @brandondacruz_Mondays Matter, Mikki's eight-week group fat loss programme.The ICECAP trial: Peos JJ et al. (2021), continuous versus intermittent dieting in resistance-trained adults. Medicine & Science in Sports & Exercise.ICECAP secondary analysis: Peos JJ et al. (2021), changes in performance, hunger and alertness across a one-week diet break. PLoS One.Siedler MR et al. (2023), continuous dieting versus diet breaks in resistance-trained women, from Bill Campbell's lab. Journal of Human Kinetics.Poon ET et al. (2025). Effects of intermittent dieting with break periods on body composition and metabolic adaptation. Systematic review and meta-analysis, Nutrition Reviews.Campbell BI et al. (2020). Intermittent energy restriction attenuates the loss of fat free mass in resistance trained individuals. Journal of Functional Morphology and Kinesiology. Plus the published comment and reanalysis by Peos and colleagues in the same journal.Dirlewanger M et al. (2000). Effects of short-term carbohydrate or fat overfeeding on energy expenditure and plasma leptin concentrations in healthy female subjects. International Journal of Obesity.Friedl KE et al. (2000). Endocrine markers of semistarvation in healthy lean men in a multistressor environment (US Army Ranger training). Journal of Applied Physiology.Barbara Rolls, research on energy density, food volume and satiety.Lyle McDonald, The Ultimate Diet 2.0.Earlier episodes in this collaboration on rapid fat loss, and on why fat loss maintenance can be harder than fat loss.Find Mikki on Instagram, Threads and X at @mikkiwilliden, on Facebook at Mikki Williden Nutrition, and at mikkiwilliden.com. Curranz Supplement: Use code MIKKIPEDIA to get 20% off your first order - go to www.curranz.co.nz  or www.curranz.co.uk to order yours NZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nz Contact Mikki:

  6. Sep 20

    Fasting Claims, Collagen for Cellulite, and Who to Trust in Women's Health

    Episode Summary A solo Mini-Mikkipedia. Mikki is often asked how to tell whether someone in the women's health space is worth following, and in this episode she answers it by working through two examples of what she thinks has gone wrong: practitioners who build large audiences on free information and then, in her view, monetise their followers' insecurities. The first half is physiology. Mikki takes two specific claims made about fasting — that it preserves muscle through growth hormone, and that it raises GLP-1 enough to make a medication unnecessary — and explains why she thinks both are wrong: the anabolic effect needs IGF-1, which needs protein and energy, and GLP-1 is a nutrient-sensing hormone that responds to food arriving in the gut. She is careful to separate that from where she thinks fasting genuinely earns its place, and to state the version of the GLP-1 claim that can be defended. The second half looks at a collagen supplement marketed for cellulite: what the one cellulite trial actually found, what a 2025 review found once industry-funded trials were separated out, and why she thinks cellulite is the wrong thing to be selling women anything for. She closes with the people she does think are worth following. Mikki is explicit that this is her opinion — "I'm just telling you what I think" — and equally explicit that she is not making a supplement of her own. Key Topics How to judge whether someone in the women's health space is worth following, and the pattern Mikki looks for: free information that turns out to be a funnelWhy Mikki fact-checked Fast Like a Girl and concluded the evidence base was mechanistic, preclinical or wrong, and what she has seen in clients who followed the protocolWhere fasting genuinely earns its place — severe insulin resistance, some gut issues, and as a researched adjunct in cancer treatment — and why 12 hours overnight is not really fastingThe growth hormone argument: why an increase in growth hormone without an increase in IGF-1 does not build or protect muscle, and why the reported percentage increases are inflated by a near-zero baselineWhy fasting cannot raise GLP-1, since GLP-1 is secreted by enteroendocrine L-cells in response to protein, fat and fermentable fibre arriving in the gut — and the one version of the claim that can be defendedThe collagen supplement marketed on the back of a story about cellulite, and Mikki's objection to the marketing rather than to collagen itselfWhat the cellulite trial actually found: 105 women, 2.5 g of collagen peptides daily for six months, a 9% reduction in cellulite score at normal BMI and 4% above BMI 25 — and nothing replicating it in the decade sinceThe 2025 review of 23 trials where collagen improved skin hydration, elasticity and wrinkles overall, but showed no effect in the trials without industry fundingWhy Mikki thinks cellulite is the wrong focus altogether, and her answer to the pushback that she talks about women's bodies herselfWho she suggests following instead, and why she has turned down several approaches to make her own supplementChapters 00:00 Introduction and Fast Like a Girl03:15 Where fasting is genuinely useful05:33 Growth hormone, IGF-1 and the GLP-1 claim09:46 Mary Claire Haver's cellulite supplement13:20 Collagen, funding and the wrong focus16:55 Who to follow in women's health Guest / Resources Guest No guest — a solo Mini-Mikkipedia episode. People discussed Dr Mindy Pelz — author of the Fast Like a Girl system, discussed critically throughout the first halfDr Mary Claire Haver — discussed in relation to a collagen supplement marketed for celluliteDom D'Agostino — referenced for his research on ketogenic diets and fasting, including fasting as an adjunct to cancer treatmentPeople Mikki recommends following Hailey Babcock — Hailey Happens Fitness, strength training and nutrition for women in midlifeDr Abbie Smith-Ryan — Professor of Exercise Physiology and Nutrition, University of North Carolina at Chapel HillDr Stacy Sims — exercise physiologist and nutrition scientist, known for her work on female athletesJen Kirsch and Holly Nicholson — also named by Mikki as people worth followingStudies and research discussed Schunck M, Zague V, Oesser S, Proksch E. Dietary Supplementation with Specific Collagen Peptides Has a Body Mass Index-Dependent Beneficial Effect on Cellulite Morphology. Journal of Medicinal Food, 2015;18(12):1340–1348. The cellulite trial Mikki describes: 105 women aged 24–50 with moderate cellulite, randomised to 2.5 g bioactive collagen peptides or placebo daily for six monthsMyung S-K, Park Y. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. The American Journal of Medicine, 2025. 23 randomised controlled trials, 1,474 participants. Collagen improved skin hydration, elasticity and wrinkles overall, but trials without industry funding showed no effect on any of the threeCollagen peptides, pain and function in active adults — research from Michael Ormsbee's lab at Florida State University, in physically active adults aged 40–65, using 10 g of collagen peptides daily for six months. This is the pain and function work Mikki refers to, and the source of the 10 g comparison she drawsIngredients discussed Fortibone — collagen peptide type discussed for bone and tendon healthVerisol — collagen peptide type studied for skin, and used in the cellulite trial aboveConcepts covered GLP-1 and enteroendocrine L-cells · growth hormone and IGF-1 · insulin resistance · time-restricted eating · mechanistic and preclinical versus clinical evidence · industry funding and publication bias Contact Mikki:https://mikkiwilliden.com/https://www.facebook.com/mikkiwillidennutritionhttps://www.instagram.com/mikkiwilliden/https://linktr.ee/mikkiwillidenNZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nzSave 20% on all Nuzest Products WORLDWIDE with the code MIKKI at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.comCurranz supplement: MIKKI saves you 25% at www.curranz.co.nz or www.curranz.co.uk off your first order

  7. Sep 15

    Dr Robert Kushner on GLP-1s, appetite biology and coming off the drug

    Save 20% on all Nuzest Products WORLDWIDE with the code MIKKIPEDIA at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.comCurranz Supplement: Use code MIKKIPEDIA to get 20% off your first order - go to www.curranz.co.nz  or www.curranz.co.uk to order yours NZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nz Episode Summary This week Mikki talks with Dr Robert Kushner, an obesity medicine physician, educator and researcher with over four decades in the field. He is Professor Emeritus at Northwestern University Feinberg School of Medicine, a founder and the first chair of the American Board of Obesity Medicine, and a past president of The Obesity Society. He was also the corresponding author on the STEP 1 semaglutide trial published in the New England Journal of Medicine in 2021, and sat on the steering committee for SELECT — so he has watched this field from the inside, before and after GLP-1 receptor agonists arrived. The conversation traces what clinicians actually understood about obesity in the 1980s and 90s, Bob's own leptin trial and why it did not deliver, and how reframing obesity as a biological disease led researchers to the gut hormones. From there it moves into the practical territory: how the clinical conversation has shifted from counting calories to diet quality, which side effects are real and which are social media noise, what happens to muscle mass and physical function, how dose escalation should actually work, why hunger returning is not the same as weight regain, and what the evidence says about stopping. Bob is careful throughout to separate what the trials show from what is still unknown, which makes this a useful listen whether you work with clients on these medications or are weighing them up yourself. Key Topics What clinicians believed about obesity three decades ago — excess body fat was known to cause system-wide harm, but the mechanisms, and appetite dysregulation in particular, were not understood, and weight regain after lifestyle intervention was already expectedBob's own leptin trial in the 1990s, published in JAMA, and why leptin turned out to be a useful biological signal rather than a treatment — it defends against weight loss but was never built to stop overeatingThe STEP 1 result and why it changed the field: 15% average weight loss at 68 weeks against a previous benchmark of 6–9%, with a third of participants losing 20%How the clinical conversation shifted from quantity to quality — when the medication does the heavy lifting, the questions become whether someone is eating enough, staying hydrated and getting sufficient protein, rather than how to control cravingsWhich side effects are real and which are overstated: GI effects are the genuine shared profile and can be substantially reduced through diet during dose escalation, while hair thinning and facial fat loss follow large weight loss by any routeMuscle mass, sarcopenia and the groups who need watching, alongside the consistent finding that physical function and quality of life improve in trials — possibly because fatty infiltration of muscle resolvesDose escalation in the real world versus the trial protocol, and why there are still no pretreatment predictors of who will respondWhy appetite drifting back is normal and not a failure — Bob's framing of restored appetite regulation at a lower body weight, with "the amplitude smaller than it was before"Benefits beyond weight loss, including SELECT's 20% reduction in cardiovascular events on top of standard care, plus sleep apnoea, knee osteoarthritis, MASH and psoriasis — driven both by weight loss and by independent mechanismsCost and access, microdosing, extending the interval between injections, and where bariatric surgery still fitsChapters 00:00 Introduction05:13 Obesity medicine before GLP-1s13:34 Gut hormones and the STEP 1 result21:00 From calorie counting to diet quality25:00 Side effects and social media myths29:54 Muscle mass, function and exercise35:08 Dose escalation and who responds40:30 When hunger comes back46:37 Stopping the drug, cost and access52:24 Benefits beyond weight loss57:37 Long-term safety and microdosing1:01:10 Coming off, surgery and what's next Guest / Resources Dr Robert Kushner Professor Emeritus, Northwestern University Feinberg School of MedicineFounder and first chair of the American Board of Obesity MedicinePast president of The Obesity SocietyAuthor or editor of 15 books, 56 book chapters and 230 original and review articlesWebsite: drrobertkushner.comBooks Six Factors to Fit: Weight Loss that Works for You! — written for the patientPatient-Centered Weight Management: The Six Factor Professional Program and Toolkit — written for the clinicianTrials and studies discussed STEP 1 — once-weekly subcutaneous semaglutide, New England Journal of Medicine, 2021. 1,961 adults, 68 weeks, ~15% average weight loss. Bob was the corresponding authorSTEP 1 extension — the off-treatment follow-up showing weight regain after stoppingSELECT — semaglutide versus placebo in 17,000 people with obesity or overweight and pre-existing cardiovascular disease but no diabetes, over nearly four years. A 20% reduction in second heart attack, stroke or cardiovascular death, on top of standard care. Bob sat on the steering committeeSURMOUNT-1 extension — participants with pre-diabetes maintained on treatment for three years, with weight remaining stableLook AHEAD — an intensive behavioural therapy trial in diabetes; of those who lost 10% of body weight, around 40% maintained it for about four years without medicationKushner's leptin trial (1990s) — placebo versus leptin injections, published in JAMAA tirzepatide dose-reduction study — 15mg reduced to 5mg, with partial weight regainA randomised microdosing study in people with diabetes — standard monthly dose escalation versus gradual weekly escalation to the same final dose, showing better tolerability and fewer dropouts. Bob refers to this study but does not name it, so it is referred-to-but-not-identifiedResearchers mentioned Andres Acosta, Mayo Clinic — phenotype and biomarker work on predicting treatment responseOrganisations Northwestern University Feinberg School of MedicineAmerican Board of Obesity MedicineThe Obesity SocietyObesity Action CoalitionNovo Nordisk — the sponsor of STEP 1Mayo ClinicMedications and hormones discussed GLP-1 receptor agonists; semaglutide; liraglutide; tirzepatide; phentermine; topiramate; naltrexone; bupropion. Gut hormones: GLP-1, GIP, glucagon, amylin. Also leptin, insulin, statins, beta blockers, testosterone and oestrogen. Terms that come up Appetite dysregulation; food noise; leptin resistance; medu...

  8. Sep 13

    A Normal HbA1c Can Hide a Decade of Insulin Resistance

    Episode Summary HbA1c turns up on almost every routine blood panel, and in this Monday mini episode Mikki looks at how much it can genuinely tell you. She starts with the physiology — haemoglobin picks up glucose non-enzymatically, red cells live 100 to 120 days, and the result is a weighted average of glucose exposure that leans heavily on the most recent month. That matters more than it first appears, because anything that shortens or lengthens red cell lifespan moves the number without blood glucose changing at all. Iron deficiency, heavy menstrual bleeding, foot strike haemolysis in runners, thalassaemia and sickle trait, recent blood donation and B12 deficiency can each push a result in one direction or the other. From there Mikki works through the research-based critiques: insulin resistance and beta cell decline can precede an abnormal HbA1c by many years, the test is highly specific but only about 50 per cent sensitive against an oral glucose tolerance test, an average conceals the shape of the glucose curve, and both genetics and ordinary measurement noise move the number independently of glucose. She closes on the practical side — where HbA1c does earn its place, why she still thinks a result of 40 or 41 deserves a conversation with your doctor, and which markers are worth reading alongside it. Key Topics What HbA1c actually measures. Glycation is non-enzymatic with no regulatory brake, so it proceeds in proportion to how much glucose is around and how long the cell is exposed. A red cell cannot repair it, making it a passive record of the preceding 8 to 12 weeks.The "three-month average" is weighted, not even. About 50 per cent of the movement toward a new value happens in the first month, which is why a result can shift over six weeks.Falsely low results. Haemolysis of any cause, haemoglobinopathies such as sickle trait and thalassaemia trait, ongoing blood loss, blood donation, recent transfusion, advanced liver disease, and starting iron treatment in someone iron deficient.Falsely high results. Untreated iron deficiency anaemia, B12 and folate deficiency, splenectomy or functional asplenia, and aplastic anaemia.Athletes get it from both directions. Foot strike haemolysis lowers A1c relative to true glucose exposure, while the iron deficiency common in female athletes raises it — and the two distortions can partly cancel out, so the number alone will not tell you which is happening.Correcting iron can drop A1c without any dietary change. Mikki's worked example is a woman going from 42 to 37 mmol/mol once her iron is sorted, and her concern is that the change gets credited to a nutrition intervention she never needed.The cut-offs, in New Zealand and US units. Roughly 30 to 39 mmol/mol normal, 41 mmol/mol pre-diabetes and 50 mmol/mol diabetes locally, against WHO and ADA thresholds of 42 and 48 mmol/mol. Type 2 diabetes throughout, not type 1.HbA1c is a lagging signal. Insulin markers can diverge from controls up to 20 years before diagnosis, and beta cell function is already down around 50 per cent by the time someone meets diagnostic criteria — so a normal HbA1c is compatible with a long stretch of compensated insulin resistance.Specific but not sensitive. Against an oral glucose tolerance test, sensitivity of about 50 per cent with specificity around 97 per cent, and screening work in which the HbA1c criteria missed a large majority of pre-diabetes.What to read alongside it. Fasting glucose, ideally fasting insulin, waist-to-height ratio, triglyceride-to-HDL ratio and a fasted lipid panel — plus your own historic trend rather than the population cut-off.Chapters 00:00 How HbA1c works and what distorts it03:41 Athletes, foot strike haemolysis and iron06:23 New Zealand and US cut-offs08:40 Why HbA1c lags insulin resistance12:12 Averages, genetics and measurement noise15:41 Your own trend, and ethnic differences18:41 Where HbA1c earns its place21:31 Sign-off and new recipes Guest / Resources Solo episode — no guest. Referenced in the episode World Health Organization — pre-diabetes around 42 mmol/mol (6%), diabetes at 48 mmol/mol (6.5%)American Diabetes Association — diabetes at 48 mmol/mol (6.5%)Mikki discusses findings from a number of published studies through the episode. They are described in the audio rather than cited by name, so no reference list is given here. Tests and markers discussed HbA1c · fasting glucose · fasting insulin · oral glucose tolerance test · continuous glucose monitor · HOMA2-IR · HOMA2-B · ferritin · fasted lipid panel · triglyceride-to-HDL ratio · waist-to-height ratio Find Mikki Instagram, Threads and X — Mikki WillidenFacebook — Mikki Williden NutritionWebsite — mikkiwilliden.com — one-on-one calls and the recipe portal Contact Mikki:https://mikkiwilliden.com/https://www.facebook.com/mikkiwillidennutritionhttps://www.instagram.com/mikkiwilliden/https://linktr.ee/mikkiwillidenNZ listeners - save 10% off Calocurb by using the code Mikkipedia10 at www.calocurb.co.nzSave 20% on all Nuzest Products WORLDWIDE with the code MIKKI at www.nuzest.co.nz, www.nuzest.com.au or www.nuzest.comCurranz supplement: MIKKI saves you 25% at www.curranz.co.nz or www.curranz.co.uk off your first order

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About

Mikkipedia is an exploration in all things health, well being, fitness, food and nutrition. I sit down with scientists, doctors, professors, practitioners and people who have a wealth of experience and have a conversation that takes a deep dive into their area of expertise. I love translating science into a language that people understand, so while some of the conversations will be pretty in-depth, you will come away with some practical tips that can be instigated into your everyday life. I hope you enjoy the show!

Information

  • Creator
    Mikki Williden
  • Years Active
    2020 - 2026
  • Episodes
    509
  • Rating
    Explicit
  • Copyright
    © 2026 Mikki Williden
  • Show Website
    Mikkipedia

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