Is dark chocolate good for weight loss?

No. Two meta-analyses of randomized trials found cocoa and dark chocolate did not change body weight. The 2019 review pooled 35 trials and found weight 0.24 lb (0.11 kg) lower, a difference that was not significant (95% CI from a 0.57 lb (0.26 kg) loss to a 0.11 lb (0.05 kg) gain), with BMI and waist unchanged. The 2024 review pooled 31 trials in 1986 adults eating cocoa extract or dark chocolate of at least 70 percent cocoa for 4 weeks or more, and found no effect on weight, BMI or waist.

Myth. Dark chocolate does not help you lose weight. That claim has been tested in dozens of randomized trials, and the pooled answer is no change. What the 2024 review did find was a small drop in cholesterol and blood pressure, which is a separate question.

What the trials found

The 2019 meta-analysis of 35 trials is the main synthesis on weight. Its abstract does not give the number of participants. One subgroup did show lower weight and BMI, trials giving at least 1.1 oz (30 g) of chocolate a day for 4 to 8 weeks. The abstract gives no size for that drop, and a short-trial subgroup is a weak basis for eating 1.1 oz (30 g) of chocolate every day.

The full text of the 2024 review adds detail. Total body mass was measured in 11 studies with 612 people and did not change, and BMI in 15 studies with 755 people did not change either, also within subgroups. Abdominal circumference fell by 1.5 in (3.93 cm), but that came from 3 studies in 174 people that disagreed with each other noticeably. The same review found total cholesterol 8.35 mg/dL lower, LDL 9.47 mg/dL lower and systolic blood pressure 2.52 mmHg lower.

Two single trials found less body fat without less weight. In a 6-month trial, 132 postmenopausal women added 10 g a day of 99 percent cocoa chocolate, 59 calories, to their usual diet. Fat mass fell by 1.4 lb (95% CI 0.24 to 2.5; metric: 0.63 kg, 0.11 to 1.15) and body fat by 0.79 percent, while weight did not change and the BMI drop did not reach significance. That chocolate is almost unsweetened, the control group got nothing rather than a placebo, and fat was measured by bioimpedance. In endurance athletes, 5 g of flavanol-rich cocoa powder a day for 10 weeks lowered body fat percentage against placebo. The abstract gives neither the size of the change nor the number of athletes.

A larger dose tells the more practical story. In a 2-week crossover trial, 19 postmenopausal women ate 3.5 oz (100 g) of chocolate a day. It cut their other eating by about 300 calories a day when eaten in the morning and about 150 calories in the evening, against 542 calories from the chocolate itself. Weight did not rise in those 14 days, which is too short to say much. The abstract does not say whether the chocolate was dark or milk.

Unsettled. Observational data point both ways. In the ARIC cohort of 15,732 US adults, people who ate chocolate weekly or more gained 0.39 more BMI units over six years (95% CI 0.23 to 0.55) than people who ate it less than monthly. A 2026 snapshot of 1960 Spanish adults found dark and milk chocolate eaters had lower BMI, and dark chocolate went with higher LDL cholesterol. A one-time snapshot cannot tell which came first, which is why the six-year cohort carries more weight here.

Who should be careful

Not for everyone. If you have formed calcium kidney stones, dark chocolate raises the oxalate in your urine. In a randomized trial in 58 stone formers, 3 days of dark chocolate raised urinary oxalate from 30 to 36 mg a day, and milk chocolate did not. That was a short load test, and new stones were not measured.

Heavy metals are the other caution for anyone eating dark chocolate daily. Laboratory testing of 72 US dark chocolate and cocoa products found 43 percent exceeded California Prop 65 limits for lead per serving and 35 percent for cadmium, with none over the limit for arsenic. 70 of the 72 were under the FDA interim reference level for lead. Prop 65 thresholds are very conservative, and that survey is a reason to keep portions modest.

What expert bodies say

We found no statement from the NIH, EFSA, the WHO or NICE on dark chocolate and body weight. The EU register of health claims holds a non-authorized antioxidant claim for cocoa polyphenols and nothing about weight.

How we searched

What would change this answer

• A randomized trial of six months or longer in adults with overweight, in which dark chocolate replaces an equal-calorie snack, with a sugar-matched control and weight as the main outcome. We found none published and none registered.
• Verification of the 2024 review of 19 trials in overweight and obese adults we could not open.
• A repeat of the body fat finding with ordinary sweetened dark chocolate and a proper placebo, measured by something more precise than bioimpedance.

More on dark chocolate itself, its effect on cholesterol and blood pressure, is on the dark chocolate page.

Sources

1. ev-dcwl-01 · Meta-analysis or systematic review · systematic review, meta-analysis and dose-response analysis of randomized clinical trials · n = 35 RCTs
   Meta-analysis did not suggest any significant effect of cocoa/DC supplementation on body weight (-0.108 kg, 95% CI -0.262, 0.046 P = 0.168), BMI (-0.014 kg/m2 95% CI -0.105, 0.077, P: 0.759,) and WC (0.025 cm 95% CI -0.083, 0.129, P = 0.640).
   
   Who: participants in randomized clinical trials of cocoa or dark chocolate reporting weight, BMI or waist circumference, to December 2017
   Effect: body weight -0.24 lb (95% CI -0.58 to 0.1; P = 0.168; metric: -0.108 kg, -0.262 to 0.046); BMI -0.014 kg/m2 (NS); waist +0.01 in (0.025 cm) (NS)
   Certainty: The main synthesis specifically on weight. The number of participants is not stated in the abstract; no full text in PMC.
   Crit Rev Food Sci Nutr, 2019 · checked 2026-10-07 · we read the abstract
2. ev-dcwl-02 · Meta-analysis or systematic review · subgroup analysis within a meta-analysis of randomized clinical trials · n = subgroup of 35 RCTs
   Subgroup analysis revealed that that weight and BMI were reduced with cocoa/DC supplementation ≥ 30 g chocolate per day in trials between 4-8 weeks.
   
   Who: subgroup of RCTs with cocoa or dark chocolate doses of 30 g/day or more and durations of 4 to 8 weeks
   Effect: significant reduction of weight and BMI in the >=30 g/day, 4-8 week subgroup; size not given in abstract
   Certainty: Subgroup, effect size not given in the abstract; short duration. Not a basis for advising 30 g daily.
   Crit Rev Food Sci Nutr, 2019 · checked 2026-10-07 · we read the abstract
3. ev-dcwl-03 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 31 studies, 1986 participants
   Cocoa consumption showed no effects on body weight, BMI, waist circumference, triglycerides, HDL-c and HbA1c.
   
   Who: adults with and without comorbidities in RCTs of cocoa extract or >=70% cocoa dark chocolate for >=4 weeks
   Effect: no effect on body weight, BMI or waist circumference; total cholesterol -8.35 mg/dL, LDL -9.47 mg/dL, SBP -2.52 mmHg
   Certainty: The newest synthesis; benefit for blood pressure and lipids, not for weight.
   Nutrients, 2024 · checked 2026-10-07 · we read the abstract
4. ev-dcwl-04 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 11 studies, 612 participants (body mass); 15 studies, 755 (BMI)
   The effect of cocoa consumption on total body mass was evaluated in 11 studies (n = 612) and was found to be ineffective (Figure 2A), even in the subgroup analysis (Figure S1, Supplementary Material File S2; Figure S11, Supplementary Material File S3).
   
   Who: adults in RCTs of cocoa reporting total body mass (11 studies) or BMI (15 studies)
   Effect: body mass and BMI unchanged, also in subgroup analyses; abdominal circumference -1.5 in (-3.93 cm) in 3 studies (n = 174)
   Certainty: Full text. A separate signal for abdominal circumference is only 3 studies, heterogeneity 60%.
   Nutrients, 2024 · checked 2026-10-07 · we read the fulltext
5. ev-dcwl-05 · Randomized controlled trial(s) · 6-month two-arm randomized controlled trial · n = 132
   Daily addition of 10 g of cocoa-rich chocolate to the habitual diet of postmenopausal women reduces their body fat mass and body fat percentage without modifying their weight.
   
   Who: postmenopausal women (57.2 years) adding 10 g/day of 99% cocoa chocolate (59 calories, 65.4 mg polyphenols) to their habitual diet vs no intervention
   Effect: body fat mass -1.4 lb (95% CI -2.5 to -0.24; metric: -0.63 kg, -1.15 to -0.11); body fat -0.79%; BMI -0.20 kg/m2 (95% CI -0.44 to 0.03, NS); weight unchanged
   Certainty: 99% cocoa, not ordinary dark chocolate with sugar; no placebo; impedancometry.
   Br J Nutr, 2021 · checked 2026-10-07 · we read the abstract
6. ev-dcwl-06 · Randomized controlled trial(s) · randomized controlled crossover trial · n = 19
   Chocolate consumption decreased hunger and desire for sweets (P < .005), and reduced ad libitum energy intake by ~300 kcal/day during MC and ~150 kcal/day during EC (P = .01), but did not fully compensate for the extra energy contribution of chocolate (542 kcal/day).
   
   Who: postmenopausal females eating 3.5 oz (100 g) of chocolate in the morning, in the evening/at night, or none for 2 weeks, other food ad libitum
   Effect: ad libitum intake -300 calories/day (morning) and -150 calories/day (evening) vs 542 calories/day from chocolate; body weight did not increase over 14 days
   Certainty: Chocolate type (dark or milk) is not stated in the abstract; 2 weeks is too little for a conclusion about weight.
   FASEB J, 2021 · checked 2026-10-07 · we read the abstract
7. ev-dcwl-07 · Randomized controlled trial(s) · placebo-controlled intervention study · n = —
   Cocoa intake significantly reduced body fat percentage (p = 0.020), specifically in the trunk (p = 0.022), visceral area (p = 0.034) and lower limbs (p = 0.004).
   
   Who: training endurance athletes receiving 5 g cocoa (425 mg flavanols) daily for 10 weeks vs placebo
   Effect: body fat percentage reduced (p = 0.020), trunk (p = 0.022), visceral area (p = 0.034); no change in performance
   Certainty: Cocoa powder, not chocolate; athletes; the magnitude of change is not given in the abstract.
   Food Funct, 2020 · checked 2026-10-07 · we read the abstract
8. ev-dcwl-08 · Observational data · prospective cohort analysis with linear mixed-effects models · n = 15,732 at the first visit, 12,830 at the second
   For instance, compared to participants who ate a chocolate serving less often than monthly, those who ate it 1-4 times a month and at least weekly experienced an increase in Body Mass Index (kg/m2) of 0.26 (95% CI 0.08, 0.44) and 0.39 (0.23, 0.55), respectively, during the six-year study period.
   
   Who: Atherosclerosis Risk in Communities cohort participants reporting usual frequency of a 1-oz (~28 g) chocolate serving
   Effect: BMI +0.26 (95% CI 0.08 to 0.44) at 1-4 times/month and +0.39 (0.23 to 0.55) at weekly or more vs less than monthly, over 6 years
   Certainty: Chocolate of any type, not only dark; observational study, causality not established.
   PLoS One, 2013 · checked 2026-10-07 · we read the abstract
9. ev-dcwl-09 · Observational data · cross-sectional analysis with multivariable linear regression · n = 1960
   In multivariable models without interaction terms, both dark and milk chocolate consumption were associated with lower BMI, whereas dark chocolate consumption was associated with higher LDL cholesterol.
   
   Who: adults from the SALMANTICOR population-based cohort, chocolate type and frequency of intake
   Effect: dark and milk chocolate consumption associated with lower BMI; dark chocolate associated with higher LDL cholesterol
   Certainty: Cross-sectional; ARIC (ev-dcwl-08) shows why such an association is misleading.
   Nutrients, 2026 · checked 2026-10-07 · we read the abstract
10. ev-dcwl-10 · Randomized controlled trial(s) · randomized trial · n = 58
    The consumption of dark chocolate induced a significant increase in mean urinary Ox (36 +/- 14 versus 30 +/- 10 mg/24 hr) not observed in the milk chocolate group.
    
    Who: calcium stone-forming patients randomized to milk (n = 28) or dark (n = 30) chocolate for 3 days
    Effect: urinary oxalate 36 +/- 14 vs 30 +/- 10 mg/24 h with dark chocolate; no rise with milk chocolate
    Certainty: Short load test; stone formation was not measured.
    J Ren Nutr, 2003 · checked 2026-10-07 · we read the abstract
11. ev-dcwl-11 · Laboratory or animal data · laboratory analysis of retail products · n = 72 products
    Our analysis reports that 43, 35, and 0% of the products tested exceed Prop 65 MADLs for heavy metal concentrations, respectively, of Pb, Cd, and As, while 97.2% (70 of 72) fall below US FDA IRL limits established for Pb.
    
    Who: 72 consumer dark chocolate and cocoa products bought over 2014-2022
    Effect: 43% over Prop 65 MADL for lead, 35% for cadmium, 0% for arsenic; 97.2% below FDA interim reference level for lead
    Certainty: Prop 65 thresholds are very conservative; for a daily "chocolate for weight loss" this is an argument against large portions.
    Frontiers in Nutrition, 2024 (heavy metals in 72 dark chocolate and cocoa products) · checked 2026-10-07 · we read the abstract