Does black coffee help with weight loss?

A little, if at all, and only without sugar. We found no randomized trial of brewed black coffee with weight loss as the main outcome. A meta-analysis of 13 randomized trials in 606 people concluded that caffeine might promote weight, BMI and body fat reduction. For the drink itself, three large US cohorts found each extra daily cup of unsweetened coffee went with 0.26 lb (0.12 kg) less weight gain over 4 years, and each teaspoon of sugar added to coffee went with 0.2 lb (0.09 kg) more.

Unsettled. The trial evidence is about caffeine and about green coffee extract capsules, and neither of those is a cup of black coffee. The caffeine trials were highly inconsistent, and the authors would only say caffeine might help. The coffee evidence is observational, and the effects are a fraction of a kilogram over years.

What the trials found

The dose-response meta-analysis of caffeine pooled 13 randomized trials with 606 participants. The direction favored caffeine for weight, BMI and body fat. The results were very inconsistent from trial to trial, and the abstract gives no change in kilograms. The authors concluded that caffeine intake might promote weight, BMI and body fat reduction, which is as far as the evidence goes.

Green coffee extract is made from unroasted beans and sold as capsules. An umbrella review of 5 meta-analyses found it lowered body weight by 2.7 lb (95% CI 2 to 3.4; metric: 1.22 kg, 0.92 to 1.53), BMI by 0.48 and waist by 0.22 in (0.55 cm) against placebo. A separate meta-analysis of randomized trials found that green coffee extract at 180 to 376 mg reduced waist circumference slightly (weighted mean difference -0.39, 95% CI -0.68 to -0.10). That is a supplement and the results do not transfer to brewed coffee.

For the drink people actually buy, the evidence is observational. In the Nurses' Health Studies and the Health Professionals Follow-up Study, each extra daily cup of unsweetened caffeinated coffee went with 0.26 lb (0.12 kg) less weight gain over 4 years (95% CI 0.05 to 0.18). Decaf showed the same 0.26 lb (95% CI 0.18 to 0.35; metric: 0.12 kg, 0.08 to 0.16). Each teaspoon of sugar went with 0.2 lb (0.09 kg) more gain, while cream or whitener showed no significant link.

A meta-analysis of 12 observational studies found higher coffee intake linked to a BMI 0.08 lower (95% CI 0.02 to 0.14), and no significant link with obesity. In 1,483 Spanish adults with metabolic syndrome, moving to more than 1 cup a day showed no significant link with body fat measured by DXA, and changes in decaf showed none either. A Danish cohort found more coffee went with slightly less gain in weight, fat mass and waist at the same time, but the associations were weak, and a cohort like this cannot show that coffee caused the change.

Myth. Coffee is not a weight loss drink. The best figure for black coffee is 0.26 lb (0.12 kg) less gained over 4 years per extra daily cup, from people who chose how much to drink. A teaspoon of sugar in each cup goes most of the way to cancelling that.

Who should be careful

Drinking more coffee to lose weight means more caffeine. The FDA cites 400 mg of caffeine a day, about two to three 12-fluid-ounce cups of coffee, as an amount not generally associated with negative effects for most adults. People differ in how they handle it, and some medicines and conditions change that.

Caffeine pills sold for weight loss are a different risk from a cup. The FDA estimates that toxic effects such as seizures can occur with rapid consumption of around 1,200 mg of caffeine, which is less than half a teaspoon of pure caffeine.

Not for everyone. If you are pregnant, the Nordic Nutrition Recommendations review advises staying at or below 200 mg of caffeine a day, the level the European Food Safety Authority set as safe for the fetus. Using coffee as a weight loss tool does not fit within that.

What expert bodies say

We found no expert body that recommends coffee for weight loss. The FDA statements above concern caffeine safety: 400 mg a day for most adults, and toxic effects around 1,200 mg taken rapidly. The Nordic Nutrition Recommendations review repeats the European Food Safety Authority limit of 200 mg a day in pregnancy.

How we searched

What would change this answer

• A long-term randomized trial of brewed black coffee against a caffeine-free control, with body weight as the main outcome.
• A new meta-analysis of caffeine trials that reports the change in kilograms and finds the trials agreeing with each other.

More on coffee itself, including the cholesterol evidence: Coffee.

Sources

1. ev-cfwl-01 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of RCTs · n = 606
   Thirteen RCTs with 606 participants were included in the meta-analyses.
   
   Who: adults in randomized controlled trials of caffeine intake, searched to November 2017
   Effect: 13 RCTs, 606 participants; heterogeneity I2 91 to 94%
   Certainty: Caffeine, not coffee as a drink; I2 > 90%; effect in relative units, absolute kg not given.
   Critical Reviews in Food Science and Nutrition, 2019 (Tabrizi et al., caffeine intake and weight loss, dose-response meta-analysis of RCTs) · checked 2026-10-07 · we read the abstract
2. ev-cfwl-02 · Meta-analysis or systematic review · systematic review and dose-response meta-analysis of RCTs · n = 606
   Overall, the current meta-analysis demonstrated that caffeine intake might promote weight, BMI and body fat reduction.
   
   Who: adults in 13 caffeine RCTs
   Effect: direction favors caffeine; size uncertain because heterogeneity was 91 to 94%
   Certainty: Cautious wording by the authors themselves; there is no RCT of black coffee specifically.
   Critical Reviews in Food Science and Nutrition, 2019 (Tabrizi et al., caffeine intake and weight loss, dose-response meta-analysis of RCTs) · checked 2026-10-07 · we read the abstract
3. ev-cfwl-03 · Meta-analysis or systematic review · umbrella review of interventional meta-analyses · n = 5 meta-analyses
   Data pooled from 5 eligible papers revealed that green coffee extract can reduce BW (WMD: -1.22 kg, 95% CI: -1.53 to -0.92, p < 0.001), BMI (WMD: -0.48 kg/m2, 95% CI: -0.67 to -0.29, p < 0.001) and WC (WMD: -0.55 cm, 95% CI: -0.80 to -0.31, p < 0.001).
   
   Who: adults in trials of green coffee extract supplements pooled in 5 meta-analyses
   Effect: body weight -2.7 lb (95% CI -3.4 to -2; metric: -1.22 kg, -1.53 to -0.92); BMI -0.48 kg/m2 (95% CI -0.67 to -0.29); waist -0.22 in (95% CI -0.31 to -0.12; metric: -0.55 cm, -0.80 to -0.31)
   Certainty: Green (unroasted) coffee supplement, not a drink; publication bias in primary RCTs is known.
   Crit Rev Food Sci Nutr, 2024 · checked 2026-10-07 · we read the abstract
4. ev-cfwl-04 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = —
   Green coffee extract (GCE) supplementation (180 to 376 mg) was found to reduce waist circumference (weighted mean difference (WMD) = -0.39; 95% CI: -0.68, -0.10), triglyceride levels (WMD = -0.27; 95% CI: -0.43, -0.10), high-density lipoprotein-cholesterol levels (WMD = 0.62; 95% CI: 0.34, 0.90), systolic blood pressure (WMD = -0.44; 95% CI: -0.57, -0.32), and diastolic blood pressure (WMD = -0.83; 95% CI: -1.40, -0.26).
   
   Who: participants in RCTs of coffee or coffee extract on metabolic syndrome parameters
   Effect: green coffee extract 180 to 376 mg: waist WMD -0.39 (95% CI -0.68 to -0.10)
   Certainty: Short search period; the number of RCTs and people is not given in the abstract.
   Medicina (Kaunas), 2021 · checked 2026-10-07 · we read the abstract
5. ev-cfwl-05 · Observational data · pooled prospective cohort analysis · n = —
   After multivariable adjustment, each 1 cup per day increment in unsweetened caffeinated coffee was associated with a reduction in 4-y weight gain of -0.12 kg (95 % CI: -0.18, -0.05 kg) and of -0.12 kg (95 % CI: -0.16, -0.08 kg) for unsweetened decaffeinated coffee.
   
   Who: Nurses' Health Study, Nurses' Health Study II and Health Professionals Follow-up Study participants, 4-year intervals
   Effect: unsweetened caffeinated -0.26 lb (95% CI -0.4 to -0.11; metric: -0.12 kg, -0.18 to -0.05) and decaffeinated -0.12 kg (95% CI -0.16 to -0.08) per 4 years per 1 cup/day increase
   Certainty: Observational; the effect is small (~0.22 lb (0.1 kg) over 4 years); self-report.
   American Journal of Clinical Nutrition, 2023 (Henn et al., changes in coffee intake, added sugar and long-term weight gain) · checked 2026-10-07 · we read the abstract
6. ev-cfwl-06 · Observational data · pooled prospective cohort analysis · n = —
   Adding a teaspoon of sugar was associated with a 4-y weight gain of +0.09 kg (0.07, 0.12 kg).
   
   Who: NHS, NHS II and HPFS participants
   Effect: +0.09 kg (0.07 to 0.12) per 4 years per teaspoon of sugar; cream or nondairy whitener not significant
   Certainty: Supports that 'black' (without sugar) is a condition of possible benefit.
   American Journal of Clinical Nutrition, 2023 (Henn et al., changes in coffee intake, added sugar and long-term weight gain) · checked 2026-10-07 · we read the abstract
7. ev-cfwl-07 · Observational data · meta-analysis of observational studies · n = 12 studies
   For BMI, WMD was -0.08 (95% CI -0.14, -0.02); RR was 1.49 (95% CI 0.97, 2.29).
   
   Who: adults in 12 epidemiologic studies, searched to February 2019
   Effect: BMI WMD -0.08 (95% CI -0.14 to -0.02); obesity RR 1.49 (95% CI 0.97 to 2.29), not significant
   Certainty: Synthesis of observational studies (not RCTs), hence level C; binary obesity RR 1.49 nonsignificant.
   Nutrients, 2019 · checked 2026-10-07 · we read the abstract
8. ev-cfwl-08 · Observational data · prospective cohort within a randomized trial · n = 1483
   Neither changes from no or infrequent consumption to high levels of caffeinated coffee consumption (>1 cup/day) nor any changes in decaffeinated coffee consumption showed significant associations with changes in DXA measures.
   
   Who: PREDIMED-Plus participants with metabolic syndrome, Spain, DXA at baseline, 6, 12 months and 3 years
   Effect: no significant association with DXA changes for >1 cup/day caffeinated or for any change in decaf
   Certainty: Observational, z-scores (small); nonmonotonic association.
   Clin Nutr, 2023 · checked 2026-10-07 · we read the abstract
9. ev-cfwl-09 · Observational data · longitudinal cohort · n = 2128
   Increased coffee consumption was associated with a decreased concurrent gain in body weight, fat mass and waist circumference, but the associations were weak.
   
   Who: Danish MONICA cohort participants
   Effect: weak inverse association with concurrent gain in body weight, fat mass and waist
   Certainty: Weak associations; reverse causation possible.
   Int J Obes (Lond), 2018 · checked 2026-10-07 · we read the abstract
10. ev-cfwl-10 · Position of an expert body · government consumer guidance · n = —
    For most adults, the FDA has cited 400 milligrams* a day — that's about two to three 12-fluid-ounce cups of coffee — as an amount not generally associated with negative effects.
    
    Who: most healthy adults, US
    Effect: 400 mg/day, about two to three 12-fluid-ounce cups, not generally associated with negative effects for most adults
    Certainty: A limit for caffeine in general; sensitivity varies (medications, conditions).
    US Food and Drug Administration, Spilling the Beans: How Much Caffeine is Too Much? (consumer update) · checked 2026-10-07 · we read the section
11. ev-cfwl-11 · Position of an expert body · government consumer guidance · n = —
    The FDA estimates toxic effects, like seizures, can be observed with rapid consumption of around 1,200 milligrams of caffeine, or less than 1/2 teaspoon of pure caffeine.
    
    Who: general population
    Effect: toxic effects around 1,200 mg consumed rapidly, less than half a teaspoon of pure caffeine
    Certainty: About concentrated caffeine, not a cup of coffee.
    US Food and Drug Administration, Spilling the Beans: How Much Caffeine is Too Much? (consumer update) · checked 2026-10-07 · we read the section
12. ev-cfwl-12 · Position of an expert body · scoping review for food-based dietary guidelines · n = —
    Pregnant women should not exceed the recommended daily dose of caffeine intake of 200 mg set by the European Food Safety Authority as a safe level for the fetus.
    
    Who: pregnant women
    Effect: caffeine at most 200 mg/day in pregnancy
    Certainty: Limits 'more coffee for weight loss' in pregnant women.
    Food Nutr Res, 2024 · checked 2026-10-07 · we read the abstract