Tuna canned in water offers a high amount of protein per calorie. One 3-ounce serving provides around 20 grams of protein for roughly 90–100 calories. It’s extremely low in fat and carbs, making it ...

On the former, ‘Protein contains calories; it’s a slave to the same laws of thermodynamics as all other food,’ says Men’s Health fitness director Andrew Tracey. ‘Eat too much, move too little, and ...