How many calories are in a gram of protein, carbs and fat?

Alcohol is where the label math falls apart. Nikkiey points to drinks like a can of Truly, which lists about 2 grams of carbs but holds about 100 calories. Those few carb grams account for only a small part of that. The rest comes from the alcohol itself, at about 7 calories per gram, and it isn't laid out clearly on the label. If you've been counting a drink by its carbs alone, that's a gap in the plan, not a lack of discipline on your part.

Why this matters: Nikkiey explains that knowing these values lets you divide your calorie target among protein, carbs and fat based on your goal, whether that's fat loss, building muscle or maintaining. Using 1,800 calories as an example, the total sets the budget, but the macro makeup of those calories is what she calls most important for body composition. In her video on figuring out your macros, she adds that calories tell you how much you're eating, not the quality of the fuel. Protein helps build and preserve lean muscle, carbs are your body's primary energy source and not the enemy, and fats support hormones, joints and brain function.

If you're not sure where to start, she singles out protein, since most women over 40 under-eat it. Her general target is about 1 gram per pound of body weight, worked toward gradually rather than all at once.