A much more flexible way of thinking about nutrition, it turns old-school, calorie-based dieting on its head by focusing instead on the amount of protein, carbohydrates and fats making up those calories.

Simply put, they're dietary components that give us energy—the body uses them in relatively large amounts, says Stella Volpe, Ph.D., chair of nutrition sciences at Drexel University in Philadelphia.

According to an IIFYM eating plan, if you stick to your daily macro goals, you'll automatically consume fewer calories, which can lead to weight loss and muscle gain.

To start counting macros, you'll need to estimate your target macronutrient ratio —that's the breakdown of your daily calories that will come from carbs, protein and fat.

Think of it like a personalized pie chart that takes into account your body's energy needs for your activity levels, your long-term weight goals, and your overall health.

It takes a minimal amount of effort, so you can easily jump back into counting macros whenever you feel you might benefit from it.