Nutrition

1. Nutritionpreliminary · human dataAdded 4 October 2026

   Corn fibre lowers LDL cholesterol but leaves blood sugar untouched

   A meta-analysis of randomised trials found corn-derived dietary fibre supplements lowered total cholesterol by 7.93 mg/dL and LDL cholesterol by 8.82 mg/dL, with no significant effect on blood sugar control, blood pressure, body measurements or inflammation.

   ⚠What it shows: Reasonably solid on the cholesterol result: it pools trials where people were assigned at random, and the effect held across different doses and study lengths. Everything else measured, from blood sugar to blood pressure, did not change, so the benefit is narrow.Review · Diabetes Res Clin Pract

   Full breakdown →ApoB explained →Heart Age Calculator →Effects of corn-derived dietary fibers on cardiometabolic risk factors: a systematic review and meta-analysis of randomized controlled trials. Diabetes Res Clin Pract 2026
2. Nutritionwell supported · human dataAdded 27 September 2026

   Protein powder's performance edge may just be the extra calories

   A pooled analysis of 75 trials in 1,206 athletes found protein supplements improved endurance and strength compared with no supplement, but every statistically significant benefit came from trials where the protein group also took in more total energy. The gains may reflect extra calories rather than protein itself.

   ⚠What it shows: Take the benefits with a pinch of salt: results pooled from 75 trials in 1,206 athletes, but every significant win came from studies where the supplement group also consumed more energy overall. Extra calories, not protein itself, may explain the edge.Meta-analysis · J Int Soc Sports Nutr

   Full breakdown →Energy balance explained →Protein Intake Calculator →The effectiveness of protein supplements on athletic performance and post-exercise recovery - a Bayesian multilevel meta-analysis of randomized controlled trials. J Int Soc Sports Nutr 2026
3. Nutritionpreliminary · human dataAdded 21 September 2026

   Keto improved memory in older adults with cognitive impairment, but raised LDL

   Across 12 randomised trials in 707 older adults with mild cognitive impairment or Alzheimer's disease, ketogenic dietary strategies improved overall cognition, memory and language, but not attention or executive function, and they raised total and LDL cholesterol.

   ⚠What it shows: Modest and real, but with a trade-off: results pooled from 12 trials in 707 older adults who already had cognitive impairment, so it says nothing about healthy brains. The same diets pushed up total and LDL cholesterol, which the authors flag as a cost to weigh against the benefits.Review · Arch Gerontol Geriatr

   Full breakdown →Executive function explained →Macro Calculator →Effects of ketogenic diet on cognitive impairment in older adults: a systematic review and meta-analysis. Arch Gerontol Geriatr 2026
4. Nutritionwell supported · human dataAdded 21 September 2026

   Probiotic milk drinks nudge blood pressure down

   A meta-analysis of 14 randomised placebo-controlled trials in 702 people found probiotic fermented milk lowered systolic blood pressure by 3.10 mmHg and diastolic by 1.09 mmHg, with a slightly greater effect in people whose blood pressure was already raised.

   ⚠What it shows: Credible but modest: results pooled from 14 placebo-controlled trials in 702 people, and the drop in blood pressure is small. There were hints that flattering trials were likelier to reach publication, though excluding the small extreme ones barely moved the result.Meta-analysis · Br J Nutr

   Full breakdown →Fermented foods explained →Heart Age Calculator →Effect of probiotic fermented milk on blood pressure: a meta-analysis of randomised controlled trials. Br J Nutr 2013
5. Nutritionwell supported · human dataAdded 18 September 2026

   Whole milk, not dairy overall, linked to prostate cancer deaths in men

   In pooled data from 11 cohort studies of 778,929 people, total dairy intake was not linked to cancer mortality, but whole milk in men was tied to higher prostate cancer death risk, rising 43% per daily serving.

   ⚠What it shows: Reassuring on dairy overall, but treat the milk finding with care: these studies followed people rather than testing diets on them, so heavy milk drinkers may differ in other ways. The prostate signal came from a subgroup and only just reached statistical significance.Meta-analysis · Nutr J

   Full breakdown →All-cause mortality explained →Healthy Lifestyle & Life Expectancy →Dairy products intake and cancer mortality risk: a meta-analysis of 11 population-based cohort studies. Nutr J 2016
6. Nutritionpreliminary · human dataAdded 16 September 2026

   Time-restricted eating gave exercisers a small extra fat loss without costing muscle

   Pooled results from 11 trials in 602 adults with overweight or obesity found that adding time-restricted eating to exercise produced modest extra losses of 1.64 kg body weight and 1.30 kg fat mass compared with exercise plus a control diet, without reducing fat-free mass. Insulin resistance also improved, while cholesterol, blood pressure, fasting glucose and HbA1c did not differ between groups.

   ⚠What it shows: Real but modest: results pooled from 11 trials in 602 adults with overweight or obesity, and the extra losses were measured in single kilograms and centimetres. Most trials were short, so nobody knows whether the edge holds over the long run.Study · Nutr Rev

   Full breakdown →Intermittent fasting explained →Calorie Deficit Calculator →Effects of Time-Restricted Eating Combined with Exercise on Body Composition and Cardiometabolic Health in Adults with Overweight or Obesity: A Systematic Review and Meta-Analysis. Nutr Rev 2026
7. Nutritionwell supported · human dataAdded 10 September 2026

   Weight regain support works, but only by 1.56 kg a year

   Across 45 randomised trials with 7788 obese adults who had lost at least 5% of their body weight, behavioural programmes targeting both diet and physical activity reduced weight regain by an average of 1.56 kg over 12 months compared with controls.

   ⚠What it shows: About as sturdy as this field gets: results pooled from 45 trials in 7788 adults who had already lost at least 5% of their body weight, though the programmes varied a lot and the average benefit was small.Meta-analysis · BMJ

   Full breakdown →Metabolic adaptation explained →TDEE Calculator →Long term maintenance of weight loss with non-surgical interventions in obese adults: systematic review and meta-analyses of randomised controlled trials. BMJ 2014
8. Nutritionpreliminary · human dataAdded 10 September 2026

   Higher protein, stronger grip after menopause, but the gap is small

   Pooling seven studies of 8,922 postmenopausal women, those with higher protein intakes had significantly greater handgrip strength than those eating less protein, though the difference was small. They also had a lower body mass index, with no difference in age between the groups.

   ⚠What it shows: Suggestive rather than proof: results pooled from seven studies of 8,922 postmenopausal women, rated low or moderate risk of bias, and the grip difference was small. They compared women who already ate differently rather than assigning anyone a diet, so activity levels and general health could be doing part of the work.Study · Menopause

   Full breakdown →Grip strength explained →Protein Intake Calculator →Association of enhanced protein intake with handgrip strength in postmenopausal women: a systematic review and meta-analysis. Menopause 2026
9. Nutritionwell supported · human dataAdded 8 September 2026

   People with darker skin may need far more winter vitamin D than guidelines say

   Pooled individual data from 10 randomised trials in 677 people of Black or South Asian descent living at latitudes of 40 degrees north or higher suggest that keeping winter blood levels above the 25 nmol/L deficiency threshold takes 23.9 to 24.1 µg of vitamin D a day, substantially more than the equivalent estimates for White individuals and above what several agencies currently recommend.

   ⚠What it shows: Strong for estimating intake needs, unproven for health outcomes: pooled individual data from 10 trials in 677 Black and South Asian children and adults living at northern latitudes. The targets are blood levels rather than demonstrated benefits, and the authors say much more work is needed in these populations.Meta-analysis · Eur J Nutr

   Full breakdown →Vitamin D explained →Phenotypic Age Calculator →Individual participant data (IPD)-level meta-analysis of randomised controlled trials to estimate the vitamin D dietary requirements in dark-skinned individuals resident at high latitude. Eur J Nutr 2022
10. Nutritionpreliminary · human dataAdded 8 September 2026

    The Mediterranean diet's brain benefits mostly vanish in randomised trials

    In the first review of randomised trials testing the Mediterranean diet against other diets for cognition, only 8 of 66 individual cognitive outcomes favoured the Mediterranean diet while 2 favoured the controls, and there was no benefit for incident cognitive impairment or dementia, a far weaker picture than observational studies suggest.

    ⚠What it shows: The fair reading is that the trial evidence is thin, not that the diet fails: only 5 trials covering 1888 people have tested this, the prescribed diets varied so much that results could not be pooled, and the strongest trial did show gains in memory and global function. A verdict either way is premature.Systematic review · Am J Clin Nutr

    Full breakdown →Executive function explained →Effect of the Mediterranean diet on cognition and brain morphology and function: a systematic review of randomized controlled trials. Am J Clin Nutr 2018
11. Nutritionwell supported · human dataAdded 3 September 2026

    Weight loss sticks better in a group, still down 2.56 kg at two years

    A meta-analysis of 47 randomised trials found that group-based diet and physical activity programmes helped overweight and obese adults lose 3.44 kg more than controls at 12 months, with 2.56 kg of advantage still present at 24 months; programmes explicitly targeting weight loss, and men-only groups providing feedback and dietary goals, were associated with greater effectiveness.

    ⚠What it shows: About as solid as weight-loss evidence gets: results pooled from 47 trials in overweight and obese adults show a clinically meaningful loss versus controls. The programmes varied hugely in design, though, so exactly which ingredients make one group work better than another is still unclear.Meta-analysis · Appl Psychol Health Well Being

    Full breakdown →Energy balance explained →Calorie Deficit Calculator →Group-Based Diet and Physical Activity Weight-Loss Interventions: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Appl Psychol Health Well Being 2018
12. Nutritionpreliminary · human dataAdded 2 September 2026

    Coffee only looked bad for older women's bones above five cups a day

    Across roughly 10 years of repeated drink questionnaires and hip scans in 9704 women aged 65 and over, tea drinking was associated with slightly higher total hip bone density (0.718 versus 0.715 g/cm2, a difference of 0.003), while coffee showed no overall association with hip or femoral neck density. Only above five cups of coffee a day did the analysis hint at lower density.

    ⚠What it shows: Treat it as a hint rather than a verdict: researchers followed 9704 women aged 65 and over for about 10 years, repeatedly asking what they drank and scanning their hips, so they watched existing habits rather than assigning drinks. The tea difference was 0.003 g/cm2, small enough to mean little for any one woman, and the coffee signal above five cups a day came from a curve-fitting analysis rather than the main comparison.Study · Nutrients

    Full breakdown →Caffeine guide →Caffeine Half-Life Calculator →Longitudinal Association of Coffee and Tea Consumption with Bone Mineral Density in Older Women: A 10-Year Repeated-Measures Analysis in the Study of Osteoporotic Fractures. Nutrients 2025
13. Nutritionwell supported · human dataAdded 1 September 2026

    Diet tweaks alone barely shift ageing muscle in women

    Across 14 randomised trials in middle-aged and older women, nutrition-only strategies had a limited but positive effect on muscle mass, strength and function: six trials showed benefits from protein, vitamin D, vitamin D with magnesium or fish oil, while eight showed no effect at all.

    ⚠What it shows: A fair reading of a thin field: a sweep of all the trials in middle-aged and older women found just 14, and they disagreed on what to supplement, how much and for how long. That means no single nutrition strategy comes out clearly on top, and exercise appeared to shape the results in several studies.Systematic review · Calcif Tissue Int

    Full breakdown →Sarcopenia explained →Protein Intake Calculator →Nutrition Interventions on Muscle-Related Components of Sarcopenia in Females: A Systematic Review of Randomized Controlled Trials. Calcif Tissue Int 2024
14. Nutritionpreliminary · human dataAdded 1 September 2026

    Coloured rice moves the needle on blood sugar, just barely

    Across randomised trials, regularly eating pigmented rice was linked with fasting glucose lower by 1.60 mg/dL, body weight lower by 0.23 kg and diastolic blood pressure lower by 1.39 mmHg, while cholesterol, triglycerides, BMI and systolic pressure did not move.

    ⚠What it shows: Treat as a lead, not a verdict: each pooled outcome rested on 5 or fewer trials and at most 349 people, and the studies differed in rice type, duration and who took part. The improvements are also small enough to question how much they matter day to day.Systematic review · Curr Nutr Rep

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Effect of Pigmented Rice Consumption on Cardiometabolic Risk Factors: A Systematic Review of Randomized Controlled Trials. Curr Nutr Rep 2023
15. Nutritionpreliminary · human dataAdded 31 August 2026

    Probiotic yogurt shows no clear edge over the regular stuff

    Pooled results from 33 trials found probiotic yogurt barely outperformed conventional yogurt: a small rise in faecal acetate and in interleukin-10, no significant difference in C-reactive protein or oxidative stress markers, and the reviewers rate the certainty of the evidence as very low.

    ⚠What it shows: Take the nulls seriously but not as final: results pooled from 33 trials found little daylight between the two yogurts, and the reviewers themselves rate the certainty as very low. The studies disagreed with each other and their design changed some results, so a real difference could still be hiding.Meta-analysis · J Nutr Biochem

    Full breakdown →Fermented foods explained →Effect of probiotic yogurt on short-chain fatty acids, inflammation, and oxidative stress biomarkers: A systematic review and meta-analysis of randomized controlled trials. J Nutr Biochem 2026
16. Nutritionwell supported · human dataAdded 31 August 2026

    Fatty fish nudges vitamin D up, but not enough to fix a shortfall

    Pooling nine studies with 640 participants, eating fish raised blood 25-hydroxyvitamin D by an average of 4.4 nmol/L; fatty fish drove almost all of that at 6.8 nmol/L, while lean fish showed no clear effect. The authors conclude that recommended fish intakes cannot optimise vitamin D status.

    ⚠What it shows: Trustworthy but modest: results pooled from randomised trials in 640 people, and the trials largely agreed with each other on fatty fish. The longer studies suggested a bigger rise, so short trials may understate what months of regular fish eating would do.Meta-analysis · Am J Clin Nutr

    Full breakdown →Vitamin D explained →Efficacy of fish intake on vitamin D status: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2015
17. Nutritionwell supported · human dataAdded 31 August 2026

    Diet beat exercise for lowering LDL; training only shifted triglycerides

    Pooling six trials with 788 adults, diet and diet plus exercise both lowered total cholesterol, LDL cholesterol and triglycerides, while aerobic exercise alone only lowered triglycerides. No approach produced a significant change in HDL cholesterol.

    ⚠What it shows: Decent evidence, narrow base: results pooled from six trials in 788 men and women, each of which compared diet, exercise, both and a control group directly, which is rare and useful. Six trials is still few, and the trials ran from 4 weeks upwards, so this says little about years of either habit.Meta-analysis · Clin Nutr

    Full breakdown →ApoB explained →Heart Age Calculator →Comparison of aerobic exercise, diet or both on lipids and lipoproteins in adults: a meta-analysis of randomized controlled trials. Clin Nutr 2012
18. Nutritionwell supported · human dataAdded 30 August 2026

    Dieting cost hip bone density; exercise-driven weight loss did not

    In a meta-analysis of 32 randomised trials, weight loss reduced bone mineral density at the hip by about 0.008 g/cm2 and at the lumbar spine by about 0.018 g/cm2 but did not change total body BMD; calorie restriction, alone or combined with exercise, lowered hip bone density, whereas weight loss achieved through exercise training without dietary restriction was associated with increased hip BMD.

    ⚠What it shows: Solid on the direction of travel: results pooled from 32 trials in adults, with hip losses emerging after more than 4 months and spine losses mainly in calorie restriction lasting over a year. The trials differed in diets, exercise and participants, so the size of the effect for any one person remains uncertain.Meta-analysis · Osteoporos Int

    Full breakdown →Bone density explained →Calorie Deficit Calculator →The effects of weight loss approaches on bone mineral density in adults: a systematic review and meta-analysis of randomized controlled trials. Osteoporos Int 2016
19. Nutritionwell supported · human dataAdded 29 August 2026

    Cutting calories lowered blood pressure about as much as medication

    Pooled results from 32 randomised trials in 1722 adults show calorie restriction lasting one to four weeks lowered systolic blood pressure by 5.5 mmHg, an effect the authors say is similar to what medication achieves. Restriction lasting up to six months also slowed resting heart rate and improved VO2peak.

    ⚠What it shows: Strong for the short term: pooled from 32 trials in 1722 adults, the blood pressure drop looks real, but most interventions lasted weeks to months, so nobody knows whether the benefit survives once normal eating resumes. The literature search also stopped in June 2017, so newer trials are missing.Meta-analysis · Clin Nutr

    Full breakdown →Energy balance explained →Calorie Deficit Calculator →The effect of caloric restriction on blood pressure and cardiovascular function: A systematic review and meta-analysis of randomized controlled trials. Clin Nutr 2021
20. Nutritionwell supported · human dataAdded 29 August 2026

    The pigment that makes berries purple may tune blood sugar and cholesterol

    A meta-analysis of 32 randomised trials with 1491 participants found anthocyanin supplementation significantly reduced fasting glucose, post-meal glucose, glycated haemoglobin, total cholesterol and LDL cholesterol in both healthy people and those with cardiometabolic disease.

    ⚠What it shows: Fairly convincing on direction, less so on size: results pooled from 32 trials in 1491 people held up even after removing the weaker studies, but the trials disagreed with each other considerably and the best dose and formulation remain unknown.Meta-analysis · Adv Nutr

    Full breakdown →Insulin sensitivity explained →Metabolic Fitness Index →Effects of Anthocyanins on Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Adv Nutr 2017
21. Nutritionpreliminary · human dataAdded 27 August 2026

    Three glasses of milk a day tracked with higher death rates, not stronger bones

    In two large Swedish cohorts, women drinking three or more glasses of milk a day had nearly double the mortality rate of women drinking less than one glass, and higher milk intake brought no reduction in fracture risk in either sex.

    ⚠What it shows: Take it as a flag, not a verdict: 61,433 women and 45,339 men reported their own diets and were followed for up to two decades, but people already in poor health may drink differently, which is why the authors themselves urge a cautious reading.Cohort · BMJ

    Full breakdown →All-cause mortality explained →Milk intake and risk of mortality and fractures in women and men: cohort studies. BMJ 2014
22. Nutritionwell supported · human dataAdded 26 August 2026

    A fibre supplement alone shaved 1.25 kg in overweight adults

    Taking an isolated soluble fibre supplement for at least 12 weeks led to an average of 1.25 kg more weight loss in overweight and obese adults across 27 randomised trials, alongside significant drops in BMI, waist circumference, fasting insulin and insulin resistance.

    ⚠What it shows: About as solid as nutrition evidence gets: results pooled from 27 trials in 1,428 overweight or obese adults, with the reviewers rating the certainty as high. The average loss was still modest at just over a kilo, so it is a helper, not a weight-loss plan.Meta-analysis · Nutrients

    Full breakdown →Insulin sensitivity explained →Calorie Deficit Calculator →Prolonged Isolated Soluble Dietary Fibre Supplementation in Overweight and Obese Patients: A Systematic Review with Meta-Analysis of Randomised Controlled Trials. Nutrients 2022
23. Nutritionwell supported · human dataAdded 23 August 2026

    Intermittent fasting works, but no better than plain calorie counting

    A meta-analysis of 43 randomised trials in 2,483 people found intermittent fasting reduced weight, BMI, waist size and fat mass compared with no diet at all, while preserving lean mass. Against ordinary calorie restriction, though, fasting showed no advantage except a smaller waist.

    ⚠What it shows: Solid as diet evidence goes: results pooled from 43 trials in 2,483 people, with a typical study running about 3 months. The key finding is comparative: fasting beat no diet at all, but against plain calorie cutting it added nothing beyond a smaller waist.Systematic review · Front Nutr

    Full breakdown →Energy balance explained →Calorie Deficit Calculator →Effects of Intermittent Fasting in Human Compared to a Non-intervention Diet and Caloric Restriction: A Meta-Analysis of Randomized Controlled Trials. Front Nutr 2022
24. Nutritionwell supported · human dataAdded 22 August 2026

    Probiotic fermented milk quietly lowers LDL cholesterol

    A meta-analysis of 39 randomised trials in 2,237 people found probiotic fermented milk products lowered LDL cholesterol by 7.34 mg/dL and total cholesterol by 8.30 mg/dL on average, with no significant effect on HDL cholesterol or triglycerides.

    ⚠What it shows: Reasonably firm but modest: results pooled from 39 trials in 2,237 people, and the drop is small. The products, bacterial strains and doses varied widely between trials, so it is not clear which fermented milk, or which bacteria, actually does the work.Meta-analysis · Nutr Metab Cardiovasc Dis

    Full breakdown →ApoB explained →Heart Age Calculator →The effect of probiotic fermented milk products on blood lipid concentrations: A systematic review and meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis 2021

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