Best Meal Replacement & Mass Gainer Bars

Two very different goals under one category

Meal replacement and mass gainer bars solve close to opposite problems. A true meal replacement is meant to functionally stand in for a meal, with meaningful calories, protein, some fiber, and ideally some vitamins and minerals. A mass gainer bar is built to add calories on top of what you already eat, usually for someone trying to gain weight or fuel a high training volume.

Calorie count is the first thing to check, and it should match your actual goal. A bar meant to replace a meal that only has 180 calories will leave you hungry an hour later. A bar meant to add bulk that only has 200 calories will not move the needle much.

We score both types the same way on our four pillars, but we note which goal each bar is realistically built for in its best-for description.

What to check before you buy

• If you actually want to replace a meal, look for something closer to 300 to 400 calories with a real mix of protein, carbs, and some fat, not just a high protein number alone.
• If you want to add bulk, look for higher total calories and carbs, not just protein. Extra protein alone with no extra calories will not help you gain weight.
• Check for at least some vitamins and minerals if you plan to replace meals regularly rather than occasionally, since a bar with almost no micronutrients is not a great everyday meal stand-in.