In short: Most well-designed weight-loss diets lose about the same amount of weight after a year, so the “best” diet is the one you can keep. Ranked by the evidence at 12 months or longer, the Mediterranean diet comes first (good long-term weight results plus fewer heart attacks and strokes in a large trial), followed by a reduced-calorie diet with any macro mix (two years of data) and a healthy low-carb plan. Pick the one that fits your food, budget and health needs.
This list ranks eating patterns, not branded products, and nothing here is for sale. It is general education, not personal medical or nutrition advice: if you have diabetes, kidney disease, a history of disordered eating, take medicines that affect blood sugar or blood pressure, or are pregnant, plan changes with your clinician or a registered dietitian. Each diet below also has its own full guide in our diets hub.
What the research says before we rank anything
The largest comparison of named diets is a 2020 network meta-analysis in the BMJ. It pooled 121 randomized trials with 21,942 adults and 14 popular diets. At six months, low-carb and low-fat patterns produced similar weight loss compared with usual eating (about 4.6 and 4.4 kg, or roughly 10 pounds), and most diets improved blood pressure. By 12 months, weight loss had shrunk for every diet, and the heart-risk benefits had largely faded for all of them except the Mediterranean diet.
The big picture from 121 diet trials
- 121randomized trials pooled, covering 14 named dietsGe et al., BMJ 2020
- 21,942adults with overweight or obesity in those trialsGe et al., BMJ 2020
- 12 monthswhen weight loss had shrunk for every diet; only the Mediterranean diet kept its heart-risk benefitsGe et al., BMJ 2020
Checked on October 6, 2026
Head-to-head trials say the same thing. In the POUNDS LOST trial (811 adults, two years), four reduced-calorie diets with very different fat, protein and carbohydrate levels all produced similar weight loss, about 4 kg (9 pounds) on average among completers, and attending the group sessions mattered more than the macro mix. In the Stanford DIETFITS trial (609 adults, 12 months), a healthy low-fat diet and a healthy low-carb diet differed by less than a kilogram. So we rank on long-term evidence first, then health markers, how easy each plan is to stick with, nutrient adequacy and cost, exactly as our How we choose method describes.
| Item | Value |
|---|---|
| Healthy low-fat | 11.7 lb |
| Healthy low-carb | 13.2 lb |
Reported as 5.3 kg and 6.0 kg; the difference was not statistically significant. Converted to pounds (1 kg = 2.2 lb).
Source: Gardner CD et al., JAMA 2018 (DIETFITS randomized trial, 609 adults) (checked on October 6, 2026)
The 10 best diets for weight loss, ranked
Each card names who the diet suits, three evidence points, what it costs and one honest drawback. “Price” here means the cost to follow it: none of these diets requires a paid program.
The 10 best diets for weight loss, ranked by evidence
1. Mediterranean diet
Best for Long-term weight loss with heart benefits
- 2-year trial: 4.4 kg (9.7 lb) average loss
- PREDIMED: about 30% fewer major heart events vs a reduced-fat diet
- only diet whose heart-risk benefits lasted at 12 months in the BMJ 2020 analysis
Maker-stated specs
Price No fee; ordinary groceries (olive oil, nuts and fish can raise the bill) (checked Oct 6, 2026)
Drawback Calorie-dense foods such as olive oil and nuts still need portion limits for weight loss
2. Reduced-calorie diet, any macro mix
Best for People who want flexibility and to eat foods they already like
- POUNDS LOST: 811 adults, 2 years, similar loss with 35% to 65% carbohydrate
- about 4 kg (9 lb) average loss in completers
- 14% to 15% lost at least 10% of body weight
Maker-stated specs
Price No fee; ordinary groceries (checked Oct 6, 2026)
Drawback Counting or estimating calories takes effort, and weight regain after year one was common
3. Healthy low-carb diet
Best for People who prefer fewer starches and more protein and fat
- DIETFITS: 6.0 kg (13.2 lb) at 12 months
- DIRECT: 4.7 kg (10.4 lb) at 2 years
- raised HDL cholesterol in trials
Maker-stated specs
Price No fee; meat, fish and nuts can cost more (checked Oct 6, 2026)
Drawback LDL cholesterol fell less than on low-fat diets in the BMJ 2020 analysis
4. Meal-replacement plan (shakes or bars for some meals)
Best for Busy people who like simple, fixed choices
- 23 trials, 7,884 adults: about 1.4 kg (3.2 lb) more loss at 1 year than other diets
- up to 6.1 kg (13.5 lb) more with extra support
Maker-stated specs
Price Shake or bar costs vary by brand (checked Oct 6, 2026)
Drawback You still have to plan the regular meals, and long-term use is a habit to think through
5. Healthy low-fat diet
Best for People who like grains, beans, fruit and vegetables
- DIETFITS: 5.3 kg (11.7 lb) at 12 months
- BMJ 2020: largest LDL cholesterol drop of the macro patterns
- DIRECT: 2.9 kg (6.4 lb) at 2 years
Maker-stated specs
Price No fee; often the cheapest pattern (checked Oct 6, 2026)
Drawback Lost less weight than Mediterranean or low-carb in the 2-year DIRECT trial
6. DASH diet
Best for People with high blood pressure or prediabetes
- Original DASH trial lowered blood pressure within 8 weeks
- meta-analysis: 1.4 kg (3.1 lb) more weight loss than controls over 8 to 24 weeks
- low-calorie DASH did better still
Maker-stated specs
Price No fee; produce-heavy grocery list (checked Oct 6, 2026)
Drawback Most weight data are shorter than 12 months
7. Higher-protein diet
Best for People who get hungry on lower-calorie diets or want to keep muscle
- 24 trials: 0.8 kg (1.7 lb) more loss and 0.4 kg more lean mass kept than standard protein
- greater fullness in 3 of 5 studies
Maker-stated specs
Price No fee; protein foods cost more (checked Oct 6, 2026)
Drawback Average trial lasted only about 12 weeks, so long-term results are less certain
8. Intermittent fasting (time-restricted or alternate-day)
Best for People who find a daily eating window easier than counting
- BMJ 2025 analysis of 99 trials: all fasting styles beat no diet
- only alternate-day fasting edged out daily calorie cutting (1.3 kg, 2.8 lb)
- 12-month trials found no difference vs calorie counting
Maker-stated specs
Price No fee (checked Oct 6, 2026)
Drawback Alternate-day fasting had the highest dropout (38%) in a year-long trial
9. Plant-based or vegetarian diet
Best for People who prefer plant foods or want a lower-cost protein mix
- 12 trials, 1,151 adults: about 2.0 kg (4.5 lb) more loss than non-vegetarian diets
- vegan styles did best (2.5 kg)
Maker-stated specs
Price No fee; beans and lentils keep costs down (checked Oct 6, 2026)
Drawback The advantage shrank to 1.1 kg (2.5 lb) in trials lasting a year or more
10. Ketogenic (very-low-carb) diet
Best for People who do well with very few carbs and are willing to plan carefully
- 13 trials of 12 months or more: 0.9 kg (2.0 lb) more loss than low-fat
- lower triglycerides and higher HDL
Maker-stated specs
Price No fee; specialty foods can add up (checked Oct 6, 2026)
Drawback Raised LDL cholesterol on average, and very-low-carb eating is hard to keep up
All 10 diets side by side
| # | Pick | Best for | Key specs (maker-stated) | Price range | Last checked |
|---|---|---|---|---|---|
| 1 | Mediterranean diet | Long-term weight loss with heart benefits | 2-year trial: 4.4 kg (9.7 lb) average loss; PREDIMED: about 30% fewer major heart events vs a reduced-fat diet; only diet whose heart-risk benefits lasted at 12 months in the BMJ 2020 analysis | No fee; ordinary groceries (olive oil, nuts and fish can raise the bill) | Oct 6, 2026 |
| 2 | Reduced-calorie diet, any macro mix | People who want flexibility and to eat foods they already like | POUNDS LOST: 811 adults, 2 years, similar loss with 35% to 65% carbohydrate; about 4 kg (9 lb) average loss in completers; 14% to 15% lost at least 10% of body weight | No fee; ordinary groceries | Oct 6, 2026 |
| 3 | Healthy low-carb diet | People who prefer fewer starches and more protein and fat | DIETFITS: 6.0 kg (13.2 lb) at 12 months; DIRECT: 4.7 kg (10.4 lb) at 2 years; raised HDL cholesterol in trials | No fee; meat, fish and nuts can cost more | Oct 6, 2026 |
| 4 | Meal-replacement plan (shakes or bars for some meals) | Busy people who like simple, fixed choices | 23 trials, 7,884 adults: about 1.4 kg (3.2 lb) more loss at 1 year than other diets; up to 6.1 kg (13.5 lb) more with extra support | Shake or bar costs vary by brand | Oct 6, 2026 |
| 5 | Healthy low-fat diet | People who like grains, beans, fruit and vegetables | DIETFITS: 5.3 kg (11.7 lb) at 12 months; BMJ 2020: largest LDL cholesterol drop of the macro patterns; DIRECT: 2.9 kg (6.4 lb) at 2 years | No fee; often the cheapest pattern | Oct 6, 2026 |
| 6 | DASH diet | People with high blood pressure or prediabetes | Original DASH trial lowered blood pressure within 8 weeks; meta-analysis: 1.4 kg (3.1 lb) more weight loss than controls over 8 to 24 weeks; low-calorie DASH did better still | No fee; produce-heavy grocery list | Oct 6, 2026 |
| 7 | Higher-protein diet | People who get hungry on lower-calorie diets or want to keep muscle | 24 trials: 0.8 kg (1.7 lb) more loss and 0.4 kg more lean mass kept than standard protein; greater fullness in 3 of 5 studies | No fee; protein foods cost more | Oct 6, 2026 |
| 8 | Intermittent fasting (time-restricted or alternate-day) | People who find a daily eating window easier than counting | BMJ 2025 analysis of 99 trials: all fasting styles beat no diet; only alternate-day fasting edged out daily calorie cutting (1.3 kg, 2.8 lb); 12-month trials found no difference vs calorie counting | No fee | Oct 6, 2026 |
| 9 | Plant-based or vegetarian diet | People who prefer plant foods or want a lower-cost protein mix | 12 trials, 1,151 adults: about 2.0 kg (4.5 lb) more loss than non-vegetarian diets; vegan styles did best (2.5 kg) | No fee; beans and lentils keep costs down | Oct 6, 2026 |
| 10 | Ketogenic (very-low-carb) diet | People who do well with very few carbs and are willing to plan carefully | 13 trials of 12 months or more: 0.9 kg (2.0 lb) more loss than low-fat; lower triglycerides and higher HDL | No fee; specialty foods can add up | Oct 6, 2026 |
Why the Mediterranean diet is number 1
The Mediterranean diet is built on vegetables, fruit, whole grains, beans, fish, nuts and olive oil. It wins on our first two criteria together. For weight, the two-year DIRECT trial (322 adults) found an average loss of 4.4 kg on a calorie-restricted Mediterranean diet, compared with 2.9 kg on a low-fat diet; adherence was 85% at two years. For health, the PREDIMED trial followed 7,447 people at high heart risk for a median of 4.8 years: major cardiovascular events were about 30% lower with a Mediterranean diet plus extra-virgin olive oil or nuts than with a reduced-fat diet (hazard ratios 0.69 and 0.72). The BMJ 2020 analysis also found it was the only pattern whose heart-risk improvements lasted at 12 months.
Low-carb lost slightly more weight in DIRECT, so why is it third? The 2-year results for Mediterranean and low-carb were close, and the Mediterranean diet has hard-outcome evidence (fewer heart attacks and strokes) that low-carb does not have, plus a better LDL cholesterol profile. Under our order, a close tie on weight goes to the diet with stronger health-marker evidence.
The middle of the list: flexible, simple and structured
A reduced-calorie diet with any macro mix (number 2) is the most flexible choice. POUNDS LOST showed that when calories are cut, the split of fat, protein and carbohydrate matters little for weight over two years. Our calorie deficit guide and calorie calculator show where to start. Its weakness is effort: tracking takes time, and weight regain after the first year was common in every arm.
Healthy low-carb (number 3) means fewer refined starches and sugars with plenty of vegetables, protein and unsaturated fats, not a very-low-carb keto plan. It did slightly better than low-fat in both DIETFITS and DIRECT, though the DIETFITS difference was not significant.
Meal-replacement plans (number 4) have some of the strongest one-year data of any approach: a 2019 meta-analysis of 23 trials and 7,884 adults found 1.44 kg more weight loss at one year than other diets, 2.22 kg more when both groups had support, and 6.13 kg more when the meal-replacement group also had extra support. They rank below the top three because they are a tool rather than a long-term eating pattern, and the health-marker evidence is thinner. Products vary a lot, so check protein, fiber and sugar on the label.
Healthy low-fat (number 5) produced the largest drop in LDL cholesterol among the macro patterns in the BMJ analysis and 5.3 kg of loss in DIETFITS, but it trailed in the two-year DIRECT trial. DASH (number 6) is the strongest choice if blood pressure is your main concern: the original 1997 trial lowered it within eight weeks, and a 2016 meta-analysis found 1.42 kg more weight loss than control diets over 8 to 24 weeks. It sits at 6 only because most of its weight data are shorter than our 12-month bar.
Higher protein, fasting, plant-based and keto
A higher-protein diet (number 7) adds modest benefits: in 24 trials with 1,063 people, it led to 0.79 kg more weight loss, 0.87 kg more fat loss and 0.43 kg more lean mass kept than a standard-protein diet with the same calories. The trials averaged about 12 weeks, so the long-term picture is less certain. Our protein calculator estimates a daily range.
Intermittent fasting (number 8) works about as well as daily calorie cutting. A 2025 BMJ network meta-analysis of 99 trials and 6,582 adults found that every fasting style beat eating freely, but only alternate-day fasting beat daily calorie restriction, by 1.29 kg, mostly in shorter trials. In trials of 24 weeks or more, no fasting style beat calorie restriction. Our comparison of intermittent fasting vs calorie counting goes through the trials one by one.
A plant-based or vegetarian diet (number 9) beat non-vegetarian diets by about 2.0 kg in a 12-trial meta-analysis, with vegan diets doing best, but the advantage was 1.13 kg in trials of a year or more. The keto diet (number 10) did produce 0.91 kg more weight loss than low-fat diets in 13 trials lasting at least a year, with better triglycerides and HDL, but LDL cholesterol rose on average, and very-low-carb eating is hard to sustain. If you take diabetes or blood pressure medicines, talk with your clinician before starting it.
How to choose the right diet for you
Choosing a diet in four steps
- Start with your healthHigh blood pressure points toward DASH or Mediterranean; high triglycerides toward lower-carb; high LDL toward Mediterranean or low-fat. Ask your clinician.
- List foods you loveThe diet you can keep for a year beats a "better" diet you quit in a month.
- Set a calorie targetEvery pattern on this list works through a calorie deficit. Use the calorie calculator for a starting point.
- Check back at 12 weeksIf weight, hunger and energy are going the right way, keep going; if not, switch patterns rather than give up.
If you are not sure where to begin, Find My Options asks a few questions about your goals and preferences. To make any diet easier, build meals around high-volume, high-protein foods from our best filling foods list, and see the wider nutrition hub for meal ideas.
What no diet can do
No eating pattern on this list removes fat from one chosen body area, speeds up your metabolism in a big way, or keeps weight off without ongoing habits. In long trials such as POUNDS LOST, weight regain began after the first year, whatever the diet. Planning for keeping weight off from the start (regular weigh-ins, steady activity, a pattern you enjoy) matters as much as the choice of diet. For people with obesity-related health conditions, diet can be combined with medical treatment; see our lose weight hub for every option.