Nutrition for weight loss

Losing weight means taking in less energy than you use, but how you cut back matters. Eat less of the wrong things and you can end up hungry, tired and short of nutrients. Eat less of the right things and it becomes much easier to stick with. Here are the nutrition basics worth knowing.

Where calories come from

Food energy comes from three macronutrients, plus alcohol:

• Carbohydrates: 4 calories per gram. The body's main fuel. They range from sugars to the starches and fiber in whole grains, beans, vegetables and fruit.
• Protein: 4 calories per gram. Needed to build and repair muscle and other tissues.
• Fat: 9 calories per gram, more than twice as much as the others. Some fat is essential, but high-fat foods add calories quickly.
• Alcohol: 7 calories per gram, with no nutrients to show for it.

No single macronutrient is the enemy. Studies comparing low-fat and low-carbohydrate diets generally find that both can work, and that the best diet is the one you can keep to.

Protein and fiber keep you full

Two things make a lower-calorie diet much easier to live with:

• Protein tends to keep you satisfied longer than the same calories from carbohydrate or fat, and it helps preserve muscle while you lose weight. Include some at every meal: fish, poultry, lean meat, eggs, dairy, beans, lentils, tofu or nuts.
• Fiber adds bulk and slows digestion. Vegetables, fruit, beans and whole grains are rich in it, and most Americans eat far less than recommended.

Foods that are high in water and fiber, such as vegetables, salads, broth-based soups and fruit, let you eat a satisfying amount for relatively few calories.

Build a balanced plate

A simple way to plan meals without counting every calorie:

• Fill about half your plate with vegetables and fruit.
• Fill about a quarter with protein.
• Fill about a quarter with grains or starchy foods, preferably whole grains.
• Add a modest amount of healthy fat, such as olive oil, nuts or avocado.
• Drink water, unsweetened tea or coffee, or milk, instead of sugary drinks.

Know what you're eating

Some foods pack a lot of calories into a small space with few nutrients: candy, pastries, chips, sugary drinks and many fast-food items. A king-size candy bar can have as many calories as a small meal and leave you hungry soon after. You don't have to give these foods up, but they are the easiest place to cut back.

The Nutrition Facts label on packaged food in the United States shows calories, serving size, fiber and "added sugars." Checking the serving size is especially useful, since a package often holds more than one.

Do you need supplements?

When you eat less, it is more important that what you eat is nutritious. Most people who eat a varied diet don't need supplements, but some may, including people on very low-calorie diets, vegans, people who have had weight-loss surgery, and those taking appetite-reducing weight-loss medications. A basic multivitamin may be reasonable in those cases; your doctor or a registered dietitian can advise you. Be wary of supplements sold for weight loss, which rarely do what they claim. Read more about vitamins and supplements and mineral supplements.

For a practical eating plan, see eating to lose weight, and for the bigger picture, our page on weight loss.

Sources

• Dietary Guidelines for Americans, 2025–2030 (US Departments of Agriculture and Health and Human Services)
• Steps for losing weight (US Centers for Disease Control and Prevention)
• Multivitamin/mineral supplements: fact sheet for consumers (NIH Office of Dietary Supplements)

Last reviewed November 2026. This article is general information, not medical advice.