Are bananas good for weight loss?

Only when a banana takes the place of something else. We found no randomized trial and no systematic review of ripe bananas and body weight. The nearest randomized evidence is about fruit and vegetables in general, and it says adding them does not make you lose weight. A meta-analysis of 7 trials found a standardized difference of 0.04, which is no effect. A larger meta-analysis of 169 controlled feeding trials in 10,357 people found that fruit lowered body weight when it was eaten in place of other foods, or added at low doses up to 10 percent of energy.

Myth. A banana does not burn fat, and eating more of them on top of your usual diet has not been shown to take weight off. The randomized trials of simply eating more fruit and vegetables found no weight loss.

Unsettled. The opposite worry, that bananas are too sweet to eat while dieting, has no support either. In three US cohorts of 133,468 adults, fruit with a higher glycemic load went with no more weight gain than fruit with a lower one. That is observational data, and bananas were counted inside total fruit with no figure of their own.

What the trials found

Fruit added to a diet

The 2014 meta-analysis pooled randomized trials that told people to eat more fruit and vegetables, or delivered the produce to their homes, for at least 8 weeks. Across 7 trials the standardized difference in weight was 0.04, with an interval from -0.10 to 0.17. The authors concluded that these recommendations do not cause weight loss. Bananas were not studied on their own.

Fruit eaten instead of other food

The 2023 meta-analysis of 169 controlled trials of at least two weeks looked at food sources of sugars. Most had no effect on weight. Fruit was among the sources that lowered it, in trials where fruit replaced other foods and in trials adding it at up to about 50 g of sugars a day. The quality of evidence was generally moderate. The abstract gives no kilogram figure for fruit, and bananas are not separated out.

What happens in everyday life

Observational data link fruit to slightly less weight gain. Across 17 cohorts of 563,277 adults, each extra 3.5 oz (100 g) of fruit a day went with 13.7 g less weight gain a year, an interval of 4.4 to 23.0 g, and the authors rated the studies as low quality. In the three US cohorts followed up to 24 years, each extra daily serving of fruit went with 0.53 lb less weight gain over four years. These figures describe people who ate more fruit, and those people differ in other ways too.

Green banana and resistant starch

Unripe banana carries resistant starch, and this is where most banana weight claims come from. The evidence is weak and mostly about supplements. A systematic review of 11 human studies found resistant starch had no direct effect on body weight or body composition, and its effect on appetite was inconsistent. A meta-analysis of 22 randomized trials in 670 people found resistant starch type 2 lowered weight only in type 2 diabetes, by 2.8 lb (1.29 kg) in 90 people, and the authors warned that a few small positive studies drove the result against most of the trials. Those supplements were not banana.

Two trials did show weight change. In 113 middle-aged adults with prediabetes or type 2 diabetes, 40 g a day of cooked green banana biomass with diet advice for 24 weeks was followed by lower body weight and fat mass within that group, and the abstract does not report a comparison between groups. In 37 adults with overweight or obesity, a resistant starch supplement for 8 weeks gave a mean loss of 6.2 lb (2.8 kg) in a crossover trial against placebo. A 2025 review of 12 green banana biomass studies, people and rats together, called the anti-obesity effect only potential.

Who should be careful

Not for everyone. According to the NIH Office of Dietary Supplements, people with chronic kidney disease, or taking ACE inhibitors or potassium-sparing diuretics, can develop high blood potassium even from dietary intakes below the adequate intake. A weight-loss plan built on bananas is a potassium plan, and those people should agree it with whoever treats them.

Latex allergy is the other caution. In a clinic series of 25 people with latex allergy, 13 also had food allergies and banana was among the most frequent, with cross-reactivity between latex, avocado, chestnut and banana. For people with diabetes, a 12-week pilot trial in 45 adults tested 250 or 18 oz (500 g) of banana a day at breakfast and called 250 g a day harmless. It was small, and its abstract did not report weight, so it says nothing about the larger dose and body weight.

What expert bodies say

We found no position from NIH, EFSA, WHO or the NHS on bananas and weight specifically. The only agency statement on this page is the NIH potassium caution above.

How we searched

What would change this answer

• A randomized trial of ripe bananas eaten in place of a snack of similar energy, with body weight as the outcome. Nothing like it has been registered.
• A banana-specific estimate from the large cohorts, which already hold the data but report bananas only inside total fruit.
• A green banana trial that reports the difference between groups rather than change within one group, in people without diabetes.

More on the fruit itself, its potassium and glycemic numbers, is on the banana page.

Sources

1. ev-bwl-01 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 7 trials
   Studies to date do not support the proposition that recommendations to increase F/V intake or the home delivery or provision of F/Vs will cause weight loss.
   
   Who: randomized trials of increased fruit and vegetable intake with body weight as an outcome, at least 15 subjects per arm and at least 8 weeks
   Effect: SMD 0.04 (95% CI -0.10 to 0.17), P = 0.62 for 7 studies; SMD -0.16 (95% CI -0.78 to 0.46) for the 2 studies meeting all criteria
   Certainty: Fruits and vegetables overall, not banana; without energy restriction. The main answer to "a banana by itself won't make you lose weight".
   Am J Clin Nutr, 2014 · checked 2026-10-07 · we read the abstract
2. ev-bwl-02 · Meta-analysis or systematic review · systematic review and meta-analysis of controlled feeding trials · n = 10,357
   Most other food sources had no effect, with some showing decreases (particularly fruits at lower doses ≤10%E or 50 g/d).
   
   Who: controlled trials of at least 2 weeks of food sources of fructose-containing sugars, searched through April 2022
   Effect: fruits decreased body weight in substitution trials and in addition trials at 10%E or less (about 50 g/d sugars); GRADE generally moderate
   Certainty: Banana is not singled out; "fruit" as a source of sugars. The effect in kg for fruit is not named in the abstract.
   Am J Clin Nutr, 2023 · checked 2026-10-07 · we read the abstract
3. ev-bwl-03 · Observational data · meta-analysis of prospective cohort studies · n = 563,277
   Higher intake of fruits was inversely associated with weight change (decrease) (beta-coefficient per 100-g increment, -13.68 g/year; 95% CI, -22.97 to -4.40).
   
   Who: adults in 17 prospective cohort studies (20 reports) on habitual fruit and vegetable intake
   Effect: -13.68 g/year per 3.5 oz (100 g) fruit (95% CI -22.97 to -4.40); highest vs lowest fruit intake OR 0.83 (0.71 to 0.99) for adiposity
   Certainty: Observational, low study quality (per the authors). Banana not singled out.
   PLoS One, 2015 · checked 2026-10-07 · we read the abstract
4. ev-bwl-04 · Observational data · pooled analysis of three prospective cohort studies · n = 133,468
   Pooled across all three cohorts, increased intake of vegetables was associated with a weight change of -0.25 lb per daily serving over 4y (95% CI, -0.35 to -0.14 lb), and fruits, -0.53 lb per daily serving (95% CI, -0.61 to -0.44 lb).
   
   Who: US men and women in the Nurses' Health Study, NHS II and Health Professionals Follow-up Study, 1986 to 2010; total fruit included bananas
   Effect: -0.53 lb per daily serving over 4 years (95% CI -0.61 to -0.44)
   Certainty: Banana is part of "total fruit", and the article has no separate number for banana (full text and S1 Fig checked).
   PLoS Med, 2015 · checked 2026-10-07 · we read the fulltext
5. ev-bwl-05 · Observational data · pooled analysis of three prospective cohort studies · n = 133,468
   We found no evidence of effect modification by fiber content or GL of fruits.
   
   Who: US men and women in three prospective cohorts, fruits grouped by fiber content and glycemic load
   Effect: -0.57 lb per daily serving of lower-fiber, higher-GL fruits (95% CI -0.80 to -0.35) vs -0.40 lb for higher-fiber, lower-GL fruits (95% CI -0.58 to -0.21)
   Certainty: Banana is classed in the appendix as high-fiber, high-GL; the data do not support the myth "banana is sweet, so it makes you fat".
   PLoS Med, 2015 · checked 2026-10-07 · we read the fulltext
6. ev-bwl-06 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 670
   However, these outcomes were heavily influenced by positive results from a small number of individual studies which contradicted the conclusions of the majority of trials.
   
   Who: RCTs of at least 8 g/day resistant starch type 2 in healthy people and those with overweight, metabolic syndrome, prediabetes or type 2 diabetes
   Effect: body weight MD -2.8 lb (95% CI -5.3 to -0.37; metric: -1.29 kg, -2.40 to -0.17) in T2DM (n = 90); trials 1 to 12 weeks, mostly unclear risk of bias
   Certainty: RS2 supplements (often corn), not banana; the effect rests on several small studies.
   Nutrients, 2019 · checked 2026-10-07 · we read the abstract
7. ev-bwl-07 · Meta-analysis or systematic review · systematic review · n = 11 studies
   Based on the results, RS intake had no direct effect on body weight and body composition.
   
   Who: human studies of dietary resistant starch intake published 2000 to 2019
   Effect: no direct effect on body weight or composition; inconsistent effects on energy intake and satiety
   Certainty: No meta-analysis; designs are mostly RCTs.
   Crit Rev Food Sci Nutr, 2021 · checked 2026-10-07 · we read the abstract
8. ev-bwl-08 · Randomized controlled trial(s) · randomized controlled trial · n = 113
   In the experimental group (G1), consumption of RS was associated with reduction in HbA1c (P = 0·0001), fasting glucose (P = 0·021), diastolic blood pressure (P = 0·010), body weight (P = 0·002), BMI (P = 0·006), waist and hip circumferences (P < 0·01), fat mass percentage (P = 0·001) and increase in lean mass percentage (P = 0·011).
   
   Who: middle-aged subjects with pre-diabetes or diabetes, nutritional support plus green banana biomass 40 g (about 4.5 g resistant starch) vs diet alone for 24 weeks
   Effect: within-group reduction in body weight (P = 0.002), BMI (P = 0.006) and fat mass percentage (P = 0.001) in the banana biomass group; between-group difference not reported in abstract
   Certainty: Green banana (cooked biomass), not ripe; changes within the group, not between groups.
   Br J Nutr, 2019 · checked 2026-10-07 · we read the abstract
9. ev-bwl-09 · Randomized controlled trial(s) · randomized placebo-controlled crossover trial · n = 37
   Here, we show that RS supplementation for 8 weeks can help to achieve weight loss (mean -2.8 kg) and improve insulin resistance in individuals with excess body weight.
   
   Who: participants with overweight or obesity, resistant starch supplement vs placebo, crossover
   Effect: mean -6.2 lb (-2.8 kg) after 8 weeks; improved insulin resistance
   Certainty: Resistant starch supplement, not a banana; small study.
   Nat Metab, 2024 · checked 2026-10-07 · we read the abstract
10. ev-bwl-10 · Randomized controlled trial(s) · systematic review · n = 12 studies
    The results of human studies indicate that the ingestion of green banana biomass controlled intestinal dysfunction (50-300 g/day for 5-14 days or 30 g/day for 8 wk) in children, and showed potential anti-obesogenic, anti-hyperlipidemic, and antidiabetic (40 g/day for 24 wk) effects in adults.
    
    Who: human and animal studies of cooked peeled or unpeeled green banana biomass, 2001 to 2021
    Effect: potential anti-obesogenic effects in adults (40 g/day for 24 wk) and rats; no pooled estimate
    Certainty: Mixes humans and rats; human RCTs on unit weight. Level A by review design, weak strength.
    Nutr Rev, 2025 · checked 2026-10-07 · we read the abstract
11. ev-bwl-11 · Randomized controlled trial(s) · randomized controlled trial (pilot, two dose arms) · n = 45
    Although it remains to be confirmed with larger group of volunteers, this pilot study has demonstrated that daily consumption of banana (@ 250 g/day) is harmless both in diabetic and hypercholesterolemic volunteers and marginally beneficial to the later.
    
    Who: thirty hypercholesterolemic and fifteen type 2 diabetic subjects, 250 or 500 g banana daily for breakfast for 12 weeks
    Effect: fasting glucose 99 to 92 mg/dL (250 g/d) in hypercholesterolemic subjects; no significant glucose or lipid change in diabetics
    Certainty: Pilot, small; weight not given in the abstract (no full text). The value is the safety of banana in diabetes.
    Indian J Exp Biol, 2014 · checked 2026-10-07 · we read the abstract
12. ev-bwl-12 · Position of an expert body · government fact sheet · n = —
    However, in people with impaired urinary potassium excretion due to chronic kidney disease or the use of certain medications, such as angiotensin converting enzyme (ACE) inhibitors or potassium-sparing diuretics, even dietary potassium intakes below the AI can cause hyperkalemia [11].
    
    Who: people with impaired urinary potassium excretion
    Effect: no UL for potassium in healthy people; hyperkalemia risk with CKD, ACE inhibitors, potassium-sparing diuretics
    Certainty: For a healthy person a banana is safe; caution for risk groups.
    NIH Office of Dietary Supplements, Potassium Fact Sheet for Health Professionals · checked 2026-10-07 · we read the section
13. ev-bwl-13 · Observational data · prospective clinical series · n = 25
    The most frequent food hypersensitivities were to avocado (9), chestnut (9), banana (7), kiwi (5) and papaya (3).
    
    Who: outpatients with latex IgE-mediated allergy
    Effect: food allergy in 13 of 25 (52%); banana in 7; cross-reactivity latex-avocado-chestnut-banana by RAST inhibition
    Certainty: Latex-fruit syndrome; applies to people with latex allergy.
    Ann Allergy, 1994 · checked 2026-10-07 · we read the abstract