Topic
Every study covered on this subject, newest first.
A registered, powered twelve week trial of a heat killed bacterial preparation missed its primary outcome in 120 overweight adults. Weight, BMI and leptin moved only in the half of participants whose gut community was least diverse to begin with, a split the authors did not plan.
Gut Microbes 18(1):2722835 · Lim et al. · the LOTTE R and D Center · 25 August 2026 · PMID 42640624
A meta-analysis pooled 11 cross sectional studies covering 1006 athletes, about half of them classified as having low energy availability. The classified group differed on body composition, bone density Z score and cortisol. Leptin showed no significant difference, and because every study measured everything at one moment, none of it establishes cause.
European Journal of Clinical · Han et al. · Yongin University · 19 August 2026 · PMID 42618779
Stripping the gut microbiome of male mice cut voluntary wheel running, and feeding back the short chain fatty acids that gut microbes normally make restored it. A fibre rich diet pushed running above normal and came with more striatal histamine.
mSystems, article e0087626 · Hutchinson et al. · the University of Illinois at Urbana-Champaign · 19 August 2026 · PMID 42615618
Sixty four adults aged 45 to 65 took creatine or a matched placebo for twelve weeks, some alongside an exercise and weight loss programme and some without. Creatine increased lean tissue mass and strength in both settings. The cognitive and blood marker results, which are the ones currently driving the supplement's marketing, are labelled exploratory by the authors themselves.
Journal of the International · Chun et al. · Texas A and M University · 11 August 2026 · PMID 42578920
Twenty eight healthy adults received an identical short chain fatty acid dose targeted either to the small intestine or to the colon. Colonic delivery released more PYY, small intestinal delivery released more GLP-1, which is the opposite of what the authors expected.
The American Journal of · Rosseel et al. · KU Leuven · 10 August 2026 · PMID 42575284
Muscle biopsies from 107 women aged 19 to 70 show that the main estrogen receptor in skeletal muscle is about half as abundant in the oldest group as in the youngest, and that receptor levels track proteins governing nitric oxide and oxidative balance. Everything measured here is protein abundance. No oxidative stress outcome and no muscle function outcome was measured at all.
GeroScience · Tamariz-Ellemann et al. · University of Copenhagen · 7 August 2026 · PMID 42566157
Sixty grams of maltodextrin during hard intervals cut muscle glycogen use by about 40 percent and left the liver untouched. Adding caffeine and four other actives cancelled the sparing, because the riders simply went harder.
American Journal of Physiology · Hannon et al. · Manchester Metropolitan University · 4 August 2026 · PMID 42552237
Twelve weeks, food provided, calories matched between arms and set to maintain weight. Ten hours of eating against the sixteen people normally use. Weight fell 2.7 percent and 2.5 percent. Appetite hormones, inflammatory markers and eating behaviour did not separate.
Obesity 34(9):1732 to 1741 · Duan et al. · the Division of Endocrinology, Diabetes and Metabolism at Johns Hopkins University School of Medicine · 27 July 2026 · PMID 42508996
Sixteen adults spent two separate four day blocks at the same low energy availability, once on 1.5 and once on 4.0 grams of carbohydrate per kilogram per day. The endocrine response tracked the carbohydrate, the shift in fuel use did not.
Journal of Applied Physiology · Nusser et al. · Technical University of Munich · 16 July 2026 · PMID 42461760
Nine well trained female cyclists were emptied of glycogen and then fed either a great deal of carbohydrate or almost none for the next day. Power at the first ventilatory threshold fell by nineteen watts, and gross cycling efficiency fell with it. The all out sprint at the end was unaffected.
European Journal of Applied · Main et al. · the Auckland University of Technology · 2 June 2026 · PMID 42228164
Thirty nine adults with type 2 diabetes did six weeks of twenty hours fasting and six weeks of their usual life, in random order. The weight came off through a large reported calorie deficit. Leptin fell, fasting ghrelin rose, and the gut peptides did not move.
International Journal of Obesity · Kramer et al. · the Leadership Sinai Centre for Diabetes at Mount Sinai Hospital and the University of Toronto · 11 March 2026 · PMID 41814085
Three degrees of ordinary calorie cutting and four kinds of fasting, compared at matched absolute energy restriction across 167 trials and nearly twelve thousand people. The ranking came out by how much energy each regimen removed. The authors state the conclusion as a negative.
Nutrition Reviews 84(3):487 to · Wu et al. · the Shanghai Institute of Endocrine and Metabolic Diseases at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine · undefined March 2026 · PMID 40367516
Turning the question around, this team asked what plastic does to the bacterium. In a simulated digestion system, micro and nanoplastics suppressed growth, lactic acid production and the protective layer the organism secretes, by shutting down central sugar metabolism.
Journal of Hazardous Materials · Tao et al. · Central South University · 20 October 2025 · PMID 41135453
Seventeen well trained lifters, eight weeks of supervised training, both arms ten percent above maintenance at 2.2 grams of protein per kilogram, and intake statistically matched. The fasting arm did fewer repetitions, rated its daily energy lower, and gained about four kilograms less on the squat.
Journal of the International · Blake et al. · the Center for Sport Performance at California State University Fullerton · 16 April 2025 · PMID 40241374
Four arms for eight weeks: a ten hour eating window, resistance training, both, and neither. The window alone dropped more than two kilograms of body weight, and the fat mass did not move. What came off was lean tissue. Adding the training changed the answer completely.
Journal of the International · Cui et al. · the Institute of Human Movement and Sports Engineering at Zhejiang Normal University · 19 March 2025 · PMID 40108888
Thirteen world class race walkers spent five to six days on a ketogenic or a high carbohydrate diet, then everyone ate a full carbohydrate day and raced. The retooling arrived in under a week. It did not leave in a day. Carbohydrate oxidation came back to 61 and 78 percent of where it started.
The Journal of Physiology · Burke et al. · the Australian Catholic University · 19 August 2020 · PMID 32697366
Twenty nine elite race walkers trained hard for three weeks on one of three controlled diets. The ketogenic arm reached fat oxidation rates higher than any previously published. It also needed more oxygen to walk at race pace, and it was the only arm that did not improve its ten kilometre time.
The Journal of Physiology · Burke et al. · the Australian Institute of Sport · 14 February 2017 · PMID 28012184
Seven cyclists ate the same food in two different orders around an evening interval session. Going to bed with the carbohydrate already spent raised the fat side of the programme by morning, including a shift in DNA methylation. It did not raise the markers of mitochondrial building the practice is usually sold on.
Journal of Applied Physiology · Lane et al. · RMIT University · 25 June 2015 · PMID 26112242
Seven cyclists trained for five days on either a high fat or a high carbohydrate diet, then ate a full carbohydrate day. Muscle glycogen ended up identical. Pyruvate dehydrogenase activity did not. After the fat week it was lower at rest and throughout exercise, and glycogen was broken down more slowly.
American Journal of Physiology, · Stellingwerff et al. · the University of Guelph · 27 September 2005 · PMID 16188909
Seven men emptied their muscle glycogen with exhausting exercise, then ate either almost no carbohydrate or a great deal of it for two days. The high carbohydrate arm raised the glucose transporter message and lowered the message for the brake on burning carbohydrate. The low carbohydrate arm did the reverse on the fat side.
American Journal of Physiology, · Arkinstall et al. · RMIT University · 3 February 2004 · PMID 14761878
Fourteen trained cyclists ate five days of high fat and five days of high carbohydrate in a crossover. Resting muscle taken after the fat diet carried more of the message for the main fatty acid transporter, and more of the transporter protein itself.
The American Journal of · Cameron-Smith et al. · Deakin University · 1 February 2003 · PMID 12540388
Five well trained cyclists ate four weeks of a ketogenic diet with calories held constant. Glucose oxidation fell threefold, muscle glycogen use fell fourfold, and endurance time at a moderate pace was unchanged. This is the study the whole low carbohydrate argument in endurance sport is built on.
Metabolism 32(8):769 to 776 · Phinney et al. · 1 August 1983 · PMID 6865776
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