What Has the Highest Caloric Density: Proteins, Fats or Carbs?

Energy-Yielding Macronutrients

Of the six macronutrients – carbs, protein, fat, vitamins, minerals and water – only three provide energy in the form of calories. Carbs and protein each provide four calories per gram, while fat is more calorically dense at nine calories per gram. Not technically a nutrient, alcohol also has calories – seven calories per gram.

Carbs

Carbs are one of your best friends when it comes to losing weight. Why? Because if you choose wisely, carb foods can be filling, nutritious and also low-calorie. Fruits, vegetables and some whole-grain foods are rich in carbs and low in caloric density. According to Penn State nutrition researcher Dr. Barbara Rolls, foods with higher amounts of water generally have lower energy density. Many fresh fruits and vegetables contain between 75 and 95 percent water, reports the University of Kentucky Cooperative Extension Service. The fiber content of fruits and vegetables also contributes to feeling full, as fiber provides bulk to the diet. Fruits and veggies are also rich sources of vitamins and minerals; ChooseMyPlate.gov recommends half of your mealtime plate be filled with fruits and vegetables.

Protein

According to Ellie Whitney and Sharon Rolfes in “Understanding Nutrition,” protein has the greatest satiating ability of any macronutrient. Digested slowly, it helps keep you feeling full longer. Despite the fact that the caloric contribution of protein is the same as carbs, it has a lower water content than most fruits and veggies. Common protein foods are animal products that contain some fat, which raises the caloric density of the food. Examples include beef, eggs, pork, chicken, turkey and fish. The Institute of Medicine recommends that 10 to 35 percent of the calories in your diet come from protein.

Fat

Because fat is the most concentrated source of calories in your diet, limit fat intake to no more than 35 percent of calories, warns the Institute of Medicine. This is critical if you are trying to lose weight. If you have the opposite problem, and want to gain weight, make more of your food choices calorie-dense. Even so, remember that moderation is key when eating high-fat foods, as high-fat diets are associated with heart disease, stroke and development of some cancers. The type of fat you choose is also important. The 2010 Dietary Guidelines for Americans recommend that saturated fats be limited to no more than 10 percent of calories. Trans fat intake should be as low as possible, but not more than 1 percent of calories.