How to Bulk Up or Lean Down on a Plant-Based Diet

Whether you’re looking to bulk up and gain muscle or slim down while on a vegan diet, plants can provide everything you need to tackle either of these goals.

You don’t need science to tell you that losing weight or gaining muscle on a plant-based diet is possible. Just watch The Game Changers, a revolutionary documentary highlighting the many plant-based professional athletes who are excelling at their sports.

So, what's the key to leaning down or bulking up while eating vegan or plant-based? It’s all about the numbers, namely calories. “If you want to increase muscle, you have to be in a calorie surplus, consuming more calories than you expend in a day’s time while slimming down is the opposite,” says Adam Stansbury, a fitness trainer in London who’s known as the "Plant-Powered PT."

And while either bulking up or slimming down can be done on a plant-based diet, there’s one important difference: “Whole, plant-based foods are nutrient-dense but not calorie-dense,” says Karina Inkster, vegan fitness and nutrition coach in Powell River, British Columbia. “Comparing a vegan diet to eating lots of calorie-dense processed foods, it can be slightly more challenging to bulk up [on a vegan diet] and slightly less challenging to slim down,” Inkster explains. But you can definitely choose how your body responds to your diet by choosing the types of foods you eat. Here’s how to get it right.

Bulking Up on a Vegan or Plant-Based Diet

If you want to gain muscle, two main nutritional strategies should dominate your game plan: Being in a calorie surplus and getting the right amount of protein. “You have to stimulate the body to grow muscle,” Stansbury explains. “It’s an energy-intensive process and generally not something the body wants to do.”

Most nutrition professionals recommend that vegans get slightly more protein than their non-vegan counterparts if they want to build muscle. “This is just to ensure that you’re getting a wide variety of amino acids and enough of the essential amino acids, which your body can’t produce,” Inkster says.

How much more protein you need when building muscle depends on your size and activity level, as well as your body goals. Stansbury recommends at least 1.5 grams per kilogram of body weight, up to 2 grams of protein per kilogram of body weight, if you’re a bodybuilder, Inkster recommends anywhere from 1.8 to 2.5 grams of protein per kilogram of body weight, depending on your type of training and your intensity.

Vegan Foods to Help You Build Muscle

Just make sure you’re eating a variety of protein sources, such as beans, legumes, tofu, tempeh, seitan, and textured vegetable protein. Add in nuts, seeds, nut butter, and a scoop of plant-based protein powder in a smoothie in the morning. One word about protein powder? “It’s not absolutely necessary, but it boosts your protein without also boosting your carbs and fats,” Inkster says. So if you're trying to bulk up, it can help your worked muscles repair faster.

Your rate of muscle gain will largely depend on your strength training experience and regimen, Inkster says. Men who are beginners can expect to gain 1.5 to 2.5 pounds of muscle per month while women who are beginners can expect to gain .65 to a pound of muscle per month. Men on the more advanced scale will gain up to .6 pounds of muscle per month while advanced female trainees will gain, at most, .25 pounds of muscle per month.

How to Lose Weight on a Plant-Based or Vegan Diet

Losing fat and getting lean on a vegan diet is exactly the same as losing fat on a non-vegan diet. “You have to make sure you’re in a calorie deficit,” Inkster says. 

Leaning down is not complicated. Your body will respond quickly to the whole foods you eat consistently. Accomplishing it is easy if you follow the philosophy of eating the rainbow and foods you could grow (if you owned a farm). “Focus on eating a variety of different colored plant foods, especially fruits and vegetables,” Stansbury says.

Also, make sure you’re eating foods that give you lots of calorie bang for your buck like big salads that fill you up for relatively few calories, Inskter says. And of course, protein is still important to help ensure you’re losing fat, not muscle. Focus on including protein-rich foods like tofu, tempeh, alternative pastas made from beans or edamame, hemp hearts, chia seeds, nutritional yeast and textured vegetable protein.

How much fat you lose will vary, but remember that it’s about losing it permanently, not necessarily quickly. “Research by Precision Nutrition shows that a reasonable rate of fat loss is one to two pounds a week for men and .8 to 1.6 pounds for women,” Inkster says.

Bottom Line: It is possible to build muscle or lose weight on a plant-based or vegan diet.

Remember that the body takes time and resists change, Stansbury says, no matter your goal. Be patient and stay consistent with your efforts to follow a plant-based diet, either to bulk up or to lean down. Your body will undoubtedly respond.