Brewer's yeast is sometimes used as a supplement to increase energy levels and to provide chromium, B vitamins, selenium and protein. Because of the chromium Brewer's yeast contains, it may be more likely to help with weight loss than with weight gain. For weight gain, you need to significantly increase your caloric intake, which isn't that easy to do with the bitter-tasting brewer's yeast. Other, higher calorie foods would be better choices for those trying to gain weight.
Calories in Brewer's Yeast
Brewer's yeast has about 28 calories per tablespoon, which isn't very much when you take into consideration that it takes an extra 3,500 calories to gain one pound. One tablespoon of brewer's yeast has slightly more than the 23 calories found in the same amount of baker's yeast, which is what you use to make bread and other baked goods; it also has slightly more than the 25 calories-per-tablespoon of nutritional yeast, which is another type of yeast used in similar ways to brewer's yeast, and which actually tastes good. If you want to gain a pound a week, this means eating an extra 500 calories per day. With a recommended dose of just 2 tablespoons per day, you're unlikely to gain weight using brewer's yeast.
Brewer's Yeast and Weight
Brewer's yeast naturally contains some chromium, but is sometimes fortified to increase chromium levels. People may try using this type of fortified brewer's yeast for weight loss purposes, but a study published in Biological Trace Element Research in 2011 found that it has no effect on body weight. Another study, published in Diabetes Care in 2006, found that one form of chromium -- chromium picolinate -- may help limit weight gain and gains in body fat. You would be better off eating more of the foods associated with weight gain instead of trying to gain weight with brewer's yeast.
Potential Safety Concerns
Unlike baker's yeast, brewer's yeast is no longer active and won't ferment when it comes into contact with water and sugar, which means it isn't as likely to give you gas as baker's yeast, if baker's yeast hasn't been deactivated by cooking. Brewer's yeast can interact with certain medications, however, including diabetes medications, MAOI antidepressants and the narcotic Demerol. Brewer's yeast also might not be safe for people who suffer from Crohn's disease, and it may lower blood sugar in people with diabetes. Check with your doctor before supplementing your diet with brewer's yeast to make sure it is safe for you.
Better Ways to Gain Weight
Adding strength training to your exercise routine, eating snacks in addition to meals and drinking high-calorie beverages between meals instead of with meals, can all help with weight gain. Your best bet, however, is to eat more of the foods that are high in calories-per-serving but that are still nutritious, such as peanut butter, nuts, seeds, olive oil, avocado and cheese. Sometimes, it's easier to drink your calories than eat them; in this instance, drinking a smoothie may help. For a nutritious but high-calorie smoothie, blend Greek yogurt, banana, nut butter, cocoa powder, dry milk powder and flax seeds, along with a small amount of maple syrup for sweetness. Round out your meals with vegetables, fruits, whole grains and protein-rich foods.