Does intermittent fasting help with weight loss?
Short answer
Yes, but about like calorie cutting.
Fasting plans lower weight compared with eating as usual. But when matched against cutting calories every day, most trials and pooled reviews find about the same weight loss, especially in longer trials.
This page says what the research shows. It does not say whether you should try intermittent fasting.
Where the evidence stands
Each dot is one on-topic paper. Steps near the top answer the question more directly. Select a dot to see the study.
↑ Stronger evidence
-
Trials in people: weight loss
Trials that measured weight loss, compared with ordinary calorie cutting directly.
9 -
Trials in people: other measures
Trials that measured other health or performance measures.
8 -
Trials in people: lab tests or safety
Trials that measured lab tests, side effects or safety.
1 -
Population studies
Studies that followed or surveyed groups of people. They show links, not causes.
0None among the papers we read.
-
Blood levels and genes
Studies that link blood levels or genes to health.
0None among the papers we read.
↓ Weaker evidence
- Points to benefit
- Mixed
- No difference
- No direction
- Points to harm
Not on the ladder: 6 reviews of many studies (shown below), 2 opinion or narrative papers. Counts are papers, not people. Some studies appear in more than one paper.
See every studyWhat we found
- Compared with eating freely, all fasting plans and daily calorie cutting lowered weight in a pooled analysis of 99 trials with 6582 adults. Semnani-Azad 2025
- Against daily calorie cutting, fasting gave about the same weight loss in a 24-trial analysis of 1768 people: a gap of 0.26 kg that could be zero. Elortegui Pascual 2023
- Only alternate-day fasting beat calorie cutting in the 99-trial analysis (mean difference -1.29 kg), and trials of 24 weeks or more showed no such gap. Semnani-Azad 2025
- Two year-long trials split: a daytime eating window added no clear loss to calorie cutting, while 4:3 fasting lost 2.89 kg more than daily cutting. Liu 2022, Catenacci 2025
What the research says
Fasting beats eating as usual
Compared with eating freely, every fasting plan lowered weight in a pooled analysis of 99 trials. Another pooled analysis of 29 trials found time restricted eating lowered weight by -1.37 kg versus standard care, an effect its authors call small.
Not every trial agrees. In the TREAT trial of 116 adults, 16:8 eating lost -0.94 kg versus -0.68 kg on three set meals. The -0.26 kg gap could be chance.
Studies: Semnani-Azad 2025, Liu 2024, Lowe 2020
Against daily calorie cutting, about the same
A pooled analysis of 24 trials (1768 people) found fasting and daily calorie cutting gave similar weight loss: a gap of 0.26 kg that could be zero. An earlier review found twelve studies comparing the two with equal results.
In a year-long trial of 139 adults with obesity, both groups had the same calorie goal. Adding a daytime eating window lost -8.0 kg versus -6.3 kg; the -1.8 kg gap could be chance (P = 0.11).
Studies: Elortegui Pascual 2023, Welton 2020, Liu 2022
Alternate-day fasting may edge ahead, short term
In the 99-trial analysis, alternate-day fasting was the only plan to beat calorie cutting, by a mean difference of -1.29 kg. In trials of 24 weeks or more, no fasting plan beat calorie cutting.
Some trials lean toward fasting. With all diets calorie-limited for 3 months, alternate-day fasting lost - 3.14 kg more than a Mediterranean diet. A year-long trial found 4:3 fasting lost 2.89 kg more than daily cutting.
Studies: Semnani-Azad 2025, Martínez-Montoro 2025, Catenacci 2025
Some extra loss may be lean mass
An umbrella review linked fasting with less fat-free mass. In a feeding trial where all 96 people ate the same limited calories, time restricted eating added a further drop in BMI but also more lean mass loss.
Studies: Patikorn 2021, Li 2024
Most trials are small and short
An umbrella review of 130 trials found a median follow-up of about 3 months. Of 104 links it tested, 28 (27%) showed benefit, mostly on weak evidence, and only one link had high-quality evidence.
A review of 27 trials called them small and short. A 29-trial analysis found high risk of bias, and its authors call the weight effect of uncertain clinical importance.
Studies: Patikorn 2021, Welton 2020, Liu 2024
What reviews of many studies found
Reviews pool or sum up earlier studies. They are not on the ladder, because they repeat studies already counted there.
Pooled review (meta-analysis) · Semnani-Azad 2025
Pooled 99 randomized trials with 6582 adults. All fasting plans and calorie cutting lowered weight versus eating freely. Only alternate-day fasting beat calorie cutting (-1.29 kg), and not in trials of 24 weeks or more.
Systematic review · Patikorn 2021
Graded 11 meta-analyses covering 130 trials. Of 104 links, 28 (27%) showed benefit, mostly on weak evidence. Only modified alternate-day fasting lowering BMI versus regular diet had high-quality evidence.
Pooled review (meta-analysis) · Liu 2024
Pooled 29 trials with 2485 adults, each lasting 12 weeks or more. Time restricted eating lowered weight by -1.37 kg versus standard care or advice; authors call it small, with high risk of bias.
Pooled review (meta-analysis) · Elortegui Pascual 2023
Pooled 24 trials with 1768 people. Fasting plans gave about the same weight loss as daily calorie cutting (mean difference 0.26 kg). Alternate-day fasting ranked first. Nestlé funded the work.
How the research grew
The papers we read span 2020 to 2025. 12 of the 26 on-topic papers came out in 2024 to 2026. The earliest trial in people here is from 2020.
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
Each dot is one on-topic paper, colored by what it found. Rings mark key papers:
- 2020. Early large trial: 16:8 eating not better. Lowe 2020
- 2022. Year-long trial: eating window adds no clear loss. Liu 2022
- 2024. Largest trial: 5:2 fasting beat diabetes drugs on weight. Guo 2024
- 2025. Biggest review: 99 trials, fasting about equals calorie cutting. Semnani-Azad 2025
- 2025. Year-long trial: 4:3 fasting edged out daily cutting. Catenacci 2025
Who was studied
Who took part, and how many. The largest trial here had 405 people.
- Trials in people
- People in the study, log scale1101001,000
- Points to benefit
- Mixed
- No difference
- No direction
- Points to harm
Bars use a log scale: each step is ten times more people. Reviews, animal studies and papers with no count in the abstract are not shown.
Who funds this research
5 of 18 trial papers have a company stake (Keyto, Novo Nordisk, Sanofi, WW, DexCom, or fasting diet book fees); 3 lack disclosures. One key review was Nestlé-funded. Stakes sit on both sides, so confidence was not lowered.
- Company stake 5
- No disclosure in PubMed 3
- No stake declared 10
- Lowe 2020Company stake
- Pavlou 2023Company stake
- Wilkinson 2020Company stake
- Ezpeleta 2023Company stake
- Allison 2021Company stake
- Liu 2022No disclosure in PubMed
- Li 2024No disclosure in PubMed
- Catenacci 2025No disclosure in PubMed
- Kapogiannis 2024No stake declared
- Guo 2024No stake declared
- Li 2024No stake declared
- Sukkriang 2024No stake declared
- Martínez-Montoro 2025No stake declared
- Li 2021No stake declared
- Chair 2022No stake declared
- Hegedus 2024No stake declared
- Xie 2022No stake declared
- He 2022No stake declared
Funding rule. A stake is always shown. Confidence is lowered only when every supporting study comes from a party with a stake. "No disclosure in PubMed" means the PubMed record has no conflict-of-interest statement. It does not mean there is no conflict.
All 26 on-topic papers
Each paper shows what it tested, what it found, and who has a stake. Every paper also has its own page that explains how much it counts and how it fits. See every study as a list.
-
Effect of a ketogenic diet, time-restricted eating, or alternate-day fasting on weight loss in adults with obesity: a randomized clinical trial.
160 people · adults with obesity, average age 45.7
Testedmodified alternate-day fasting, early or late time restricted eating, or keto diet, all with calorie limits, vs a calorie-limited Mediterranean diet, for 3 months
Vs the calorie-limited Mediterranean diet, weight change differed by - 3.14 kg (- 4.98 to - 1.30 kg) with alternate-day fasting and - 2.27 kg (- 4.13 to - 0.40 kg) with late window, but not early window (- 1.22 kg (- 3.07 to 0.64 kg)).
MixedNo stake declaredAbstract onlyNo competing interests declared.
-
Randomized trial · measured the question itselfCatenacci et al., 2025Annals of internal medicine · PubMed
The Effect of 4:3 Intermittent Fasting on Weight Loss at 12 Months : A Randomized Clinical Trial.
165 people · adults aged 18 to 60 with overweight or obesity (BMI 27 to 46)
Testedcutting food 80% on 3 non-consecutive days a week (4:3 fasting), vs cutting daily food 34%, both with a behavior program, for 12 months
At 12 months, 4:3 fasting gave greater weight loss than daily calorie cutting (mean difference, 2.89 kg [95% CI, 5.65 to 0.14 kg]; P = 0.040). 125 of 165 finished.
Points to benefitNo disclosure in PubMedAbstract onlyNo disclosure in PubMed; funded by NIDDK.
-
Effects of healthy low-carbohydrate diet and time-restricted eating on weight and gut microbiome in adults with overweight or obesity: Feeding RCT.
96 people · adults with overweight or obesity
Testedtime restricted eating and/or low-carb diet, all fed the same limited calories, for 12 weeks plus 28 weeks follow-up
All groups lost 2.57 to 4.11 kg on the same calories. Time restricted eating added a further drop in BMI but also more lean mass loss, while the low-carb diet added fat loss.
MixedNo stake declaredAbstract onlyNo competing interests declared.
-
Randomized trial · measured the question itselfSukkriang et al., 2024Journal of diabetes investigation · PubMed
Effect of intermittent fasting 16:8 and 14:10 compared with control-group on weight reduction and metabolic outcomes in obesity with type 2 diabetes patients: A randomized controlled trial.
99 people · adults with obesity and type 2 diabetes
Tested16:8 or 14:10 fasting, 3 days a week for 3 months, vs normal controlled diet
Weight change was -4.02% with 16:8, -3.15% with 14:10 and -0.55% in controls (P < 0.001 for both fasting groups vs controls). 16:8 lost more than 14:10 (P < 0.001).
Points to benefitNo stake declaredAbstract onlyNo conflicts of interest to disclose.
-
Effect of Time-Restricted Eating on Weight Loss in Adults With Type 2 Diabetes: A Randomized Clinical Trial.
75 people · adults with obesity and type 2 diabetes
Testedeating only noon to 8 pm without counting calories, vs 25% daily calorie cutting, vs no change, for 6 months
Vs controls, weight fell -3.56% (95% CI, -5.92% to -1.20%; P = .004) with time restricted eating but -1.78% (95% CI, -3.67% to 0.11%; P = .06) with calorie cutting. HbA1c fell similarly in both.
Points to benefitCompany stakeAbstract onlyAuthor fees for a fasting diet book (The Fastest Diet); consulting fees from Rhythm Pharmaceuticals; DexCom grant and support.
-
Randomized trial · measured the question itselfLiu et al., 2022The New England journal of medicine · PubMed
Calorie Restriction with or without Time-Restricted Eating in Weight Loss.
139 people · adults with obesity
Testedeating only 8 am to 4 pm plus calorie cutting, vs calorie cutting alone (same calorie goals), for 12 months
Weight loss was -8.0 kg with time restricted eating and -6.3 kg with calorie cutting alone. Net difference -1.8 kg (95% CI, -4.0 to 0.4; P = 0.11). Body fat and risk markers matched.
No differenceNo disclosure in PubMedAbstract onlyNo disclosure in PubMed; funded by Chinese government research funds.
-
Randomized trial · measured the question itselfChair et al., 2022The journal of nursing research : JNR · PubMed
Intermittent Fasting in Weight Loss and Cardiometabolic Risk Reduction: A Randomized Controlled Trial.
101 people · overweight and obese adults with prediabetes
Testedalternate-day fasting or 16/8 time restricted fasting for 3 weeks, vs a control group, with follow-up at 3 months
Both fasting groups lost more weight, BMI and waist size than controls (all ps < .05). Alternate-day fasting cut weight and BMI more than 16/8 (all ps < .001). No numbers for weight in abstract.
Points to benefitNo stake declaredAbstract onlyNo conflicts of interest declared.
-
Time-restricted eating with or without low-carbohydrate diet reduces visceral fat and improves metabolic syndrome: A randomized trial.
adults with metabolic syndrome in China
Tested8-hour eating window, low-carb diet, or both, for 3 months
All three plans cut body weight vs baseline. Compared with the low-carb diet, eating in 8 hours and the combination further cut body weight and belly fat. No numbers given in abstract.
Points to benefitNo stake declaredAbstract onlyNo competing interests declared.
-
Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men With Overweight and Obesity: The TREAT Randomized Clinical Trial.
116 people · men and women aged 18 to 64 with BMI 27 to 43
Tested16:8 time restricted eating (eat noon to 8 pm) for 12 weeks, vs three set meals a day
Weight fell -0.94 kg with fasting and -0.68 kg with set meals; the gap was -0.26 kg (95% CI, -1.30 to 0.78; P = .63). Authors conclude it is not more effective than eating throughout the day.
No differenceCompany stakeAbstract onlyTwo authors report ties to Keyto, a weight-loss company; one co-founded it and holds equity.
-
Brain responses to intermittent fasting and the healthy living diet in older adults.
40 people · older adults with normal thinking and insulin resistance
Tested5:2 intermittent fasting vs a healthy living diet, for 8 weeks
Fasting led to more weight loss than the healthy living diet. Both diets gave similar gains in brain scans and blood markers. Main aim was brain health; no weight numbers in abstract.
MixedNo stake declaredAbstract onlyNo competing interests declared.
-
A 5:2 Intermittent Fasting Meal Replacement Diet and Glycemic Control for Adults With Diabetes: The EARLY Randomized Clinical Trial.
405 people · adults with overweight or obesity and early type 2 diabetes
Tested5:2 fasting with meal replacements vs metformin or empagliflozin (diabetes drugs), for 16 weeks
Blood sugar (HbA1c) fell most with fasting: -1.9% vs -1.6% metformin and -1.5% empagliflozin. Weight fell -9.7 kg with fasting, -5.5 kg with metformin and -5.8 kg with empagliflozin.
Points to benefitNo stake declaredAbstract onlyNo conflicts reported; no company funding listed.
-
Randomized trial · other health measuresHegedus et al., 2024Journal of the Academy of Nutrition and Dietetics · PubMed
Randomized Controlled Feasibility Trial of Late 8-Hour Time-Restricted Eating for Adolescents With Type 2 Diabetes.
27 people · teens and young adults aged 13 to 21 with type 2 diabetes
Testedeating only noon to 8 pm without counting calories, vs eating over 12 or more hours, for 12 weeks
Within the fasting group, BMI measure fell -3.4% (95%CI: -6.1, -0.7, p = 0.02), but there was no significant difference between fasting and control (all p > .05). Study was a small feasibility pilot.
No differenceNo stake declaredAbstract onlyNo financial relationships or conflicts declared.
-
Effect of alternate day fasting combined with aerobic exercise on non-alcoholic fatty liver disease: A randomized controlled trial.
80 people · adults with obesity and fatty liver disease
Testedalternate-day fasting plus exercise, fasting alone, exercise alone, or no change, for 3 months
Liver fat fell -5.48% with fasting plus exercise vs -1.30% exercise alone and -0.17% control; vs fasting alone (-2.25%) no clear gap (p = 0.05). Weight fell with the combo vs control.
MixedCompany stakeAbstract onlyOne author earned fees from Hachette for a book on alternate-day fasting.
-
Randomized controlled trial for time-restricted eating in healthy volunteers without obesity.
82 people · healthy adults without obesity
Testedearly eating window or mid-day eating window, vs no restriction (control), for 5 weeks
Early window improved insulin sensitivity more than mid-day window. Early window, but not mid-day, reduced total body mass and body fat. No weight numbers in abstract.
MixedNo stake declaredAbstract onlyNo competing interests declared.
-
Trial, not randomized · other health measuresLi et al., 2021Journal of translational medicine · PubMed
Eight-hour time-restricted feeding improves endocrine and metabolic profiles in women with anovulatory polycystic ovary syndrome.
15 people · young women with polycystic ovary syndrome and no ovulation
Testedeating within 8 hours a day for 5 weeks, one group with no comparison group
Body weight, BMI, fat mass and visceral fat fell after 5 weeks. Menstrual cycle improved in 73.3% (11/15). No weight numbers in abstract and no control group.
Points to benefitNo stake declaredAbstract onlyNo competing interests declared.
-
Prolonged, Controlled Daytime versus Delayed Eating Impacts Weight and Metabolism.
12 people · healthy adults aged about 26 with normal weight
Testedeating only 8 am to 7 pm vs only noon to 11 pm, same food and calories, 8 weeks each in a crossover
Weight and insulin resistance went down on the daytime schedule compared with the delayed one, and went up on the delayed schedule (effect size range: d = 0.397-1.019).
Points to benefitCompany stakeAbstract onlyOne author had research funding from Novo Nordisk and consulted for WW (Weight Watchers), stated as unrelated.
-
Ten-Hour Time-Restricted Eating Reduces Weight, Blood Pressure, and Atherogenic Lipids in Patients with Metabolic Syndrome.
19 people · adults with metabolic syndrome, most taking statins or blood pressure drugs
Testedeating within a 10-hour window for 12 weeks, one group with no comparison group
The title reports lower weight, blood pressure and bad blood fats after 12 weeks of 10-hour eating. The abstract gives no weight numbers and had no control group.
Points to benefitCompany stakeAbstract onlyOne author consults for Sanofi, Novo Nordisk and others and holds Cardero stock; another earns royalties on The Circadian Code.
-
Effect of 5:2 Regimens: Energy-Restricted Diet or Low-Volume High-Intensity Interval Training Combined With Resistance Exercise on Glycemic Control and Cardiometabolic Health in Adults With Overweight/Obesity and Type 2 Diabetes: A Three-Arm Randomized Controlled Trial.
326 people · adults with overweight or obesity and type 2 diabetes
Tested5:2 diet with formula meals on 2 days a week, or 2 days of exercise a week, vs routine lifestyle education, for 12 weeks
Main result was blood sugar: HbA1c fell -0.72 with the 5:2 diet vs -0.37 in controls (difference -0.34, 95% CI -0.58 to -0.11, P = 0.007). Diet and exercise both improved body fat; no weight numbers given.
Points to benefitNo disclosure in PubMedAbstract onlyNo disclosure in PubMed; government research grants only.
-
Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials.
99 studies, 6,582 people · adults, healthy or with health conditions
Testedalternate day fasting, time restricted eating and whole day fasting, vs daily calorie cutting or eating freely; mostly under 24 weeks
All fasting plans and calorie cutting lost weight vs eating freely. Vs calorie cutting, only alternate day fasting did better: mean difference -1.29 kg (95% CI -1.99 to -0.59). Trials of 24 weeks or more showed no gap.
MixedCompany stakeAbstract onlySeveral authors report fees or advisory roles with Novo Nordisk, Eli Lilly and food companies; none stated for fasting products.
-
Meal Timing and Anthropometric and Metabolic Outcomes: A Systematic Review and Meta-Analysis.
29 studies, 2,485 people · adults, mean BMI 33, 69% women
Testedtime restricted eating, fewer meals or earlier calories for 12 weeks or more, vs usual care or nutrition advice
Time restricted eating lowered weight vs control (-1.37 kg; 95% CI, -1.99 to -0.75 kg). Authors call the effect small and of uncertain clinical importance, with high risk of bias.
Points to benefitNo stake declaredAbstract onlyNo competing interests declared.
-
A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.
24 studies, 1,768 people · adults in the general population
Testedalternate day fasting, 5:2 diet and time restricted eating, vs daily calorie cutting
Fasting plans gave similar weight loss to calorie cutting: mean difference 0.26 kg (95% CI: -0.31 to 0.84; p = 0.37). Alternate day fasting ranked highest, then calorie cutting, then time restricted eating.
No differenceCompany stakeAbstract onlyFunded by Nestle; several authors are Nestle employees.
-
Intermittent Fasting versus Continuous Calorie Restriction: Which Is Better for Weight Loss?
overweight and obese adults
Testedintermittent fasting vs continuous daily calorie cutting
Body weight fell a little more with fasting than calorie cutting (SMD = -0.21, 95% CI (-0.40, -0.02) p = 0.028). BMI did not differ (SMD = 0.02, 95% CI (-0.16, 0.20) p = 0.848).
MixedNo stake declaredAbstract onlyNo competing interests declared.
-
Intermittent Fasting and Obesity-Related Health Outcomes: An Umbrella Review of Meta-analyses of Randomized Clinical Trials.
130 studies · adults, including those with overweight or obesity
Testedalternate day fasting, 5:2 diet and time restricted eating in 130 trials (median follow-up 3 months); comparison groups not stated except regular diet for one link
Of 104 links, 28 (27%) showed benefit, mostly weak evidence. One link with high-quality evidence: modified alternate-day fasting for 1 to 2 months lowered BMI vs regular diet. Fasting was also linked to less fat-free mass.
Points to benefitCompany stakeAbstract onlyOne author earns fees for a book on alternate-day fasting; another reported symposium fees.
-
Intermittent fasting and weight loss: Systematic review.
27 studies · overweight and obese adults
Testedintermittent fasting for 2 to 26 weeks (two trials lasted 1 year), vs calorie cutting or baseline weight
All 27 trials found weight loss of 0.8% to 13.0% of starting weight. Twelve studies compared fasting with calorie cutting and found equal results. Studies were small and short.
No differenceNo disclosure in PubMedAbstract onlyNo disclosure in PubMed.
-
Risks and Benefits of Intermittent Fasting for the Aging Cardiovascular System.
adults, with focus on older people and heart health
Testedintermittent fasting, summing up trials on weight, body make-up and heart risk factors
Review says fasting may help blood pressure, blood sugar and body weight, but calls for more research and caution before wide use, especially in older people. No numbers given in abstract.
No weight on the ladderNo disclosure in PubMedAbstract onlyNo disclosure in PubMed.
-
Chrononutrition in the Prevention and Management of Metabolic Disorders: A Literature Review.
people in studies of time restricted eating and metabolic disease
Testedtime restricted eating, looking at human studies from 2014 to 2024
Review says time restricted eating may help body weight and fat loss, while blood sugar and blood fat effects are unclear. It says there is no conclusive evidence yet.
No weight on the ladderNo stake declaredAbstract onlyNo conflicts of interest declared.
16 papers we read and set aside as off topic
- Conde-Pipó et al., 2024. Intermittent Fasting: Does It Affect Sports Performance? A Systematic Review. (systematic review)
- Ness-Jensen et al., 2016. Lifestyle Intervention in Gastroesophageal Reflux Disease. (systematic review)
- Stephan et al., 2024. Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis. (pooled review (meta-analysis))
- Kosiborod et al., 2024. Semaglutide in Patients with Obesity-Related Heart Failure and Type 2 Diabetes. (randomized trial)
- Sutton et al., 2018. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. (randomized trial)
- Salminen et al., 2022. Effect of Laparoscopic Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass on Weight Loss, Comorbidities, and Reflux at 10 Years in Adult Patients With Obesity: The SLEEVEPASS Randomized Clinical Trial. (randomized trial)
- Teong et al., 2023. Intermittent fasting plus early time-restricted eating versus calorie restriction and standard care in adults at risk of type 2 diabetes: a randomized controlled trial. (randomized trial)
- Petimar et al., 2020. [Not Available]. (population study: followed a group)
- Gaugel et al., 2024. Picalm, a novel regulator of GLUT4-trafficking in adipose tissue. (animal study)
- Paoli et al., 2019. The Influence of Meal Frequency and Timing on Health in Humans: The Role of Fasting. (opinion or narrative review)
- Raji et al., 2024. Chrononutrition and Cardiometabolic Health: An Overview of Epidemiological Evidence and Key Future Research Directions. (opinion or narrative review)
- Ikehata et al., 2023. Body composition and testosterone in men: a Mendelian randomization study. (gene study (mendelian randomization))
- Bryan et al., 2023. Supervised weight loss requirements disproportionately affect Black patients seeking weight loss surgery. (population study: followed a group)
- Zheng et al., 2025. Chronic low back pain causal risk factors identified by Mendelian randomization: a cross-sectional cohort analysis. (population study: one-time survey)
- Khater et al., 2025. Long-Term Effects of Intensive Lifestyle Intervention on Cardiometabolic Outcomes in Patients With Diabetes in Real-World Clinical Practice: A 15-Year Longitudinal Study. (population study: followed a group)
- Tayyem et al., 2022. Comparison of safety and efficacy of intragastric botulinum toxin-A versus gastric balloon. (population study: followed a group)
Words on this page
- SMD (standardized mean difference)
- A way to compare results measured on different scales. About 0.2 is a small effect, 0.5 medium, and 0.8 large.
- 95% CI (confidence interval)
- The range where the true result likely lies. If the range includes no effect (1 for ratios, 0 for differences), the result is not clear.
- p-value (p =)
- How likely a result this large would be by chance if there were no real effect. Below 0.05 is usually called a clear result.
- Pooled review (meta-analysis)
- A study that combines the results of many earlier studies to get one overall answer.
- Umbrella review
- A review of many pooled reviews.
- Marker
- A lab or scan result that stands in for a health outcome. A better marker does not always mean better health.
How the short answer is set
Fixed rules turn the studies into the short answer, so the same studies always give the same answer. The rules start from GRADE, a standard system for rating evidence, in plain language.
| Confidence | What it means |
|---|---|
| High | We are confident the answer is right. |
| Moderate (this page) | The answer is probably right, but it could change. |
| Low | The answer may well change. |
| Very low | Any answer is very uncertain. |
| Not tested in people | Only cell or animal studies exist. |
Why moderate here
- Many randomized trials in people measured body weight itself.
- Most trials are small and short, and many carry risk of bias.
- Results against calorie cutting mostly agree; small edges appear only for some plans.
- Company stakes sit on both sides, so they did not change confidence.
How this page was made
Label
- Search
- PubMed, Nov 14, 2026. Searches written by Claude Opus 5.5; papers ranked by PubMed
- First read of all 42 papers
- Claude Sonnet
- Independent second read
- Claude Haiku
- Disagreements settled by
- Claude Opus 5.5
- Page text written by
- Claude Opus 5.5
- Charts
- Drawn by code from the study records
- Source check by a person
- Not yet. Required before search engines may list this page.
- Expert review
- No
- Papers read in full
- 0 of 42; all from PubMed abstracts
- Method
- v0.2, created Nov 14, 2026
Search. We ran four PubMed searches for intermittent fasting and time-restricted eating and weight loss, compared with ordinary calorie cutting: pooled and systematic reviews since 2012 (10 of 274), trials in people (22 of 1,339), population studies (10 of 1,756). The first number is how many papers we read; the second is how many PubMed found. We took the ones PubMed ranks as most relevant. See the full PubMed search. Of the 42 papers read, 26 were on topic.
Limits. Digestery reads at most about 60 papers per question, so large fields are sampled, not covered in full. Abstracts can leave out key details, such as side effects and funding.
Review queue
These items wait for a person. Search engines are asked not to list the page until the first one is done.
- OpenThe short answer is new. It waits for a source check by a person.
- OpenTeong 2023: fasting vs calorie cutting trial (209 people) marked off-topic because abstract reports no weight; full text may report weight.
- OpenPavlou 2023: abstract gives fasting and calorie cutting each vs control, not the direct gap between them; check full text.
- OpenMartínez-Montoro 2025: n kept at 160 randomized; 140 finished. Check which number was analyzed.
- OpenAllison 2021: compares early vs late eating windows with the same food, not fasting vs usual eating or calorie cutting; relevance is indirect.
- OpenPooled reviews Semnani-Azad 2025, Elortegui Pascual 2023, Zhang 2022 and Welton 2020 likely share many trials; their results are not independent.
- OpenZhang 2022: number of trials and people not stated in abstract.
- OpenNo COI statement in PubMed for Liu 2022 and Li 2024; Catenacci 2025 only points to online disclosure forms.
- OpenSukkriang 2024 cites Thai registry TCTR 20230131002 in its disclosures but has no trial registration field.
Page history
| Date | Change | Reason |
|---|---|---|
| Nov 14, 2026 | Page created from 42 papers. | First version of the page. |
Flag an error
A flag must point to a source: the passage in the paper, or a link to a study this page missed. A flag starts a new check. Votes never change a page.