When it comes to food, not all calories are created equal. A carbohydrate impacts your body differently from a protein or a fat. It’s the reason a 300-calorie sesame bagel — straight carbs — just doesn’t satisfy you the same way an egg and cheese sandwich on whole-wheat bread does. But striking the right combination of carbs, proteins and fats to provide optimal nutrition and satisfaction can be a challenge. How much of each should you eat? What’s the right mix? Should you go low-fat, low-carb or low-glycemic index?

According to the American Medical Association, a low-glycemic index, or low-G-I, diet takes the cake for its ability to keep weight off. The low-G-I diet gauges the effect of carbs on blood sugar. Foods are rated on a scale from one to 100 that measures their impact. The lower the G-I score, the better.

A study at Boston University looked at each diet’s effect on energy expenditure, because when weight decreases so does the body’s ability to burn calories at a resting rate. The conundrum puts would-be weight losers at a risk for piling back the pounds.

The participants first lost 10 to 15 percent of their body weight on a three-month diet that was 45 percent carbs, 30 percent fat and 25 percent protein. Then they followed the low-fat, low-carb or low-G-I diet for four weeks at a time.

Turns out that restricting fat to 20 percent of your daily calories also restricts energy use. Low-carb dieters burned the most at 300 calories a day at rest, but also increased the stress hormone cortisol.

But the low G-I diet was just right, with these dieters burning about 150 more calories than the low-fat calorie-counters. Along with their blood sugar levels, their cholesterol and hormones remained stable, too.

So if you want to whittle your waistline for the long haul, go low with the G-I diet for lasting results.