How to lose weight and keep it off, from your own numbers

To lose weight, eat fewer calories than you burn, in a way you can keep up for years: diets with very different mixes of carbs and fat give similar results over 1 to 2 years.^{[1, 2]} A 2026 US guideline targets at least 5% to 10% of your weight.^[3] Keeping it off is linked with regular weigh-ins, and the same guideline recommends long-term support.^{[9, 3]}

Start from your own numbers

The 2026 guideline from the American Heart Association, the American College of Cardiology and others targets at least 5% to 10% of starting weight.^[3] An NIH page, drawing on the older 2013 US obesity guideline, suggests reaching 5% to 10% within 6 months.^[4] For someone who weighs 200 pounds, 5% is 10 pounds.^[11]

Modest loss already matters for health. The 2013 US obesity guideline found that a 5% loss lowered blood pressure by about 3 and 2 mm Hg (top and bottom number) on average.^[12] People at risk for type 2 diabetes may prevent or delay it by losing at least 5% to 7%.^[13] For people with overweight or obesity, losing at least 3% to 5% may reduce fat in the liver.^[13]

To see where you start, the BMI calculator gives your body mass index, and BMI explained covers who it is wrong for. Your waist-to-height ratio and body fat percentage show what BMI misses.

Low-carb, low-fat and the rest: what the trials show

In one 2-year trial, 811 adults were put on four diets with very different amounts of fat, protein and carbs.^[1] All four were set 750 calories a day below what each person burned.^[1] Loss was similar whatever the mix, 2.9 to 3.6 kg at 2 years across the comparisons.^[1]

A later trial of 609 adults aged 18 to 50 compared a healthy low-fat diet with a healthy low-carb diet for a year.^[14] Weight loss was 5.3 kg and 6.0 kg, not a significant difference.^[14] Neither diet asked people to count calories, yet both groups reported eating about 500 to 600 calories a day less.^[14]

A review of 48 trials of named diets reached the same place: the differences between diets were small.^[2] Its authors back any diet a person will stick to.^[2] The 2026 US guideline puts low-fat and low-carb plans at a modest loss of roughly 4 kg, in a review of 121 trials.^[3] For the mechanics, read what a calorie deficit is and how many calories to eat to lose weight.

A plan from one set of numbers

Dalia's app offers three paces, 0.5, 1 or 1.5 pounds a week, which it turns into a cut of 250, 500 or 750 calories a day. Dalia's app never sets a daily target below 1,200 calories.

Try your own numbers in the calorie deficit calculator. Before choosing the fastest pace, read how fast you can safely lose weight.

What to eat: diet quality matters for how much you eat

What you eat changes how much you eat. In a 4-week ward study, 20 adults were offered ultra-processed meals for 2 weeks and unprocessed meals for 2 weeks, eating as much as they liked.^[19] They ate about 508 calories a day more on the ultra-processed diet and gained 0.9 kg, while they lost 0.9 kg on the unprocessed one.^[19] It was a small, short study.

Water-rich food helped in one trial. In a year-long trial of 97 women with obesity, adding fruit and vegetables to a lower-fat diet gave more loss among those who finished, 7.9 kg against 6.4 kg, with less hunger.^[20] Neither group had a calorie goal.^[20] The 2025–2030 Dietary Guidelines say to prioritize fiber-rich whole grains, and the advisory committee behind them listed fiber as underconsumed in the US.^{[21, 22]}

Protein

Protein helps a little while you cut. Across 24 trials, people on higher-protein diets with the same calories kept about 0.43 kg more fat-free mass.^[5] The authors call the benefits modest.^[5] Higher-protein meals make people feel a little fuller, but did not cut how much they ate at the next meal.^[23]

The recommended dietary allowance (RDA) for adults, 0.8 g per kg of body weight a day, was set to prevent deficiency, not to keep the most muscle.^[22] The 2025–2030 Dietary Guidelines set higher protein goals, 1.2 to 1.6 g per kg a day, adjusted to your calorie needs.^[21] The report behind them notes that most of the 30 trials in its review of higher-protein diets were in adults with overweight or obesity who were cutting calories.^[22]

Dalia's targets, protein included, can be changed: tell the coach the number you want. Our guide to how much protein you need goes deeper.

Fasting and meal timing

Time-restricted eating has not beaten an ordinary daily cut in trials. In a 12-week trial of 116 adults, eating only from noon to 8 pm was no better than three meals a day.^[24] In a year-long trial of 139 adults on the same calorie targets, adding an 8-hour window did not add a significant loss.^[25] A 2025 review of 99 trials found some indication that fasting diets give similar results to a daily cut.^[26]

Activity and keeping weight off

Exercise on its own produces modest loss. The American College of Sports Medicine says 150 to 250 minutes a week of moderate activity gives only modest loss.^[7] More than 250 minutes a week has been linked to meaningful loss, and, in observational studies, to better maintenance after loss.^[7]

Strength training does not add to weight loss, but it may build fat-free mass and help shed fat.^[7] Across diet trials, exercise mattered more at 12 months than at 6.^[2] For keeping muscle while you lose, see losing fat without losing muscle.

Sleep changes what you lose and how much you eat

Experts recommend 7 to 9 hours of sleep a night for adults 18 to 64.^[27] In a 2-week study of 10 adults on the same diet, 5.5 hours in bed instead of 8.5 cut the share of weight lost as fat by 55% and raised the loss of fat-free mass by 60%.^[28]

In 80 adults with overweight who slept less than 6.5 hours, a single counseling session added about 1.2 hours of sleep a night.^[6] They ate about 270 calories a day less than the control group, with no diet advice.^[6]

Tracking: what the evidence says about logging and weighing

Self-monitoring, keeping track of food, activity or weight, is the core of behavioral weight loss programs.^[29] A review of 22 studies found it was consistently linked with weight loss, though the evidence was weak.^[29] For weighing, adding it to a program helped by 1.7 kg on average, while advice to weigh alone showed no clear effect in the one trial that tested it.^[30]

The habits linked with long-term success include frequent self-monitoring and self-weighing.^[9] Our guides cover how to read the scale, calorie tracking apps and how accurate photo calorie estimates are.

Why weight loss slows down

Most programs follow the same curve: fast early loss, a plateau, then slow regain.^[9] In a review of 80 trials, weight leveled off at about 6 months.^[8] By one estimate, each kilogram lost lowers daily burn by about 20 to 30 calories and raises appetite by about 100.^[9] Our guide to why the scale gets stuck works through one example.

How to keep it off

Regain is common, but on average people keep some weight off. In 29 US studies, people kept off more than 3 kg on average 5 years after a structured program.^[31] In an 8-year trial in adults with type 2 diabetes, 50.3% of the intensive lifestyle group still had at least 5% off.^[10]

About 20% of people with overweight keep off at least 10% of their weight for a year or more.^[32] People in a US registry of successful losers report about an hour of activity a day, a low-calorie, low-fat diet, regular breakfast, weighing themselves and eating the same way on weekends.^[32] These are habits members report about themselves, so they show what is possible, not proof of what works.

• Keep support going. The 2026 US guideline recommends long-term weight management programs, with more physical activity, to keep lost weight off.^[3]
• Keep weighing. In 314 adults who had recently lost weight, a program built on daily weighing cut the share who regained 2.3 kg or more.^[33]
• Expect the effort to stay. Holding off regain took about 300 to 500 calories a day of ongoing effort against the slower burn and higher appetite, in one model of two example women.^[9]

When to talk to a clinician