"An apple a day may keep extra pounds away," says Katherine Brooking, RD, co-founder of Appetite for Health. A medium apple has around 95 calories and 5 grams of filling fiber. Apple peels are also a rich source of ursolic acid, a natural plant compound that has been shown in preliminary studies to increase fat-burning. In addition, one study reported that women who added three small apples (equal to 200 calories) to their diet per day lost a little more than 2.5 pounds in 12 weeks-more than dieters who did not include the fruit in their diet.

As a plant-based, protein-packed choice, beans are one of the best foods to enjoy when you're trying to trim down. "Beans are metabolized slowly, so they may aid in weight loss by keeping you feeling fuller longer," notes Bonnie Taub-Dix, RDN. A half-cup of beans provides about 110 calories and 7 grams of protein, around the same amount of protein as you'd get in an ounce of chicken or fish. Beans are also considered a nutrient-rich superfood providing antioxidants, iron, potassium, and zinc.

Berries

Want something sweet to enjoy that can help you trim down and tone up too? Eat more berries, suggests Susan Burke March, RDN. Berries are low in calories, high in fiber, and will satisfy your cravings for something sweet without any added sugar. One study revealed that eating a snack of 65 calories of mixed berries resulted in participants eating 133 fewer calories at dinner, compared to those who ate a 65-calorie sugary treat instead. Another study that looked at the eating patterns of more than 130,000 adults for more than 20 years found that berries were one of the best fruits for maintaining a healthy weight.

Citrus fruit

A medium orange has just 60 calories and 3 grams of fiber, while a grapefruit has around 100 calories and 4 grams of fiber. Due to their high water and fiber counts, citrus fruits have lower glycemic index scores and can help temper blood sugar levels to keep you satisfied for longer.