The art of portion control means consuming the right amount of food and beverages for proper nutrition, weight maintenance and weight loss. But don’t confuse portion control with serving size-—there’s a big difference between the two.

“A serving size is a particular food’s recommended quantity based on its nutritional label, while portion size refers to how much food should be consumed at one time to avoid overeating,” says Lisa Jubilee, MS, certified dietician, nutritionist and co-owner of New York City–based Living Proof, a gym that offers integrated nutrition and personal training.

For those who want to drop some pounds, portion control is an excellent option. When you eat smaller meals, you consume fewer calories than your body burns. The result? Weight loss.

If you want to maintain your weight, then observe portion control and eat the same amount of calories that your body burns each day. Each person’s weight differs based on activity level and body composition—the amount of muscle, fat and water you carry. This composition—not body weight—health experts say, is what determines whether we’re fit and healthy.

Portions can be sized up with measuring cups, spoons and a food scale, but these tools aren’t necessary. You can use your hand as a guide.

For example, a typical portion of protein shouldn’t exceed the size of your palm including its thickness. Starches (rice, pasta and potatoes) should be the size of your fist. Veggies should equal two fists together. Top them off with pats (about the size of a thumbnail) of fats, such as butter and mayonnaise, for allowable portion-controlled tastiness.

A quality-of-life issue, portion control can also help you avoid bingeing, a type of overeating. Binge-triggering foods vary among individuals, but most overeaters abuse easy-to-eat, carb-laden salty or sweet foods, such as chips, ice cream and cakes. Lower your chances of bingeing by avoiding extreme hunger. Jubilee suggests eating small meals every three to four hours.