Whether you're adopting a vegetarian diet or trying to introduce new protein foods into your diet, tofu is a nutritious alternative to meat. This soy product is both high in protein and one of the only plant sources of all essential amino acids. In addition, raw tofu does not contain cholesterol, trans fats or dangerous amounts of saturated fats. Although non-fattening in its raw state, tofu can increase greatly in calories -- and thus become fattening -- if prepared with oils and other high-fat foods.
One pound of body fat is approximately 3,500 calories. As such, consuming 500 calories more than you burn each day results in a gain of approximately 1 pound of fat per week. A 1/2-cup serving of firm tofu contains 183 calories. This serving size provides nearly 4.5 ounce-equivalents of protein, just short of the 2010 Dietary Guidelines for Americans' suggestion of 5.5 ounce-equivalents of protein per day. Protein foods should account for 10 to 30 percent of your daily calories, so a serving of tofu is not adequately high in calories to result in a gain in body fat.
Burning and consuming calories are the main determinants of weight gain. One gram of fat contains approximately 9 calories, while 1 gram of carbohydrates or protein contains only 4 calories. With 11 grams of fat in a 1/2 cup of firm tofu, approximately 99 of the 183 calories in a serving of firm tofu come from fat. However, tofu contains very few unhealthful fats, with no cholesterol or trans fats and only 1.6 grams of saturated fats. Although regular tofu has a healthful fat profile and is not fattening because of its low caloric content, low-fat tofus can help you to further reduce your caloric intake.
The fat and caloric content of tofu generally increase with its firmness. For example, 1/2 cup of regular tofu contains 94 calories and approximately 5.9 grams of total fat. Soft tofu is even less fattening, with only 76 calories and 4.6 grams of total fat in a 1/2-cup serving. Although less fattening, these varieties also contain much less protein than firm tofu. While a 1/2-cup serving of firm tofu contains 19.9 grams of protein, the same serving of regular tofu provides 10 grams and soft tofu only 8.1 grams of protein. As even the firmest tofu is low in calories in its raw state, you should only use softer tofu if required by a recipe to avoid a drop in protein intake and change in the texture of your dish.
Tofu's absorbent properties lend it the ability to easily adopt different flavors. As it can also easily absorb the fats in other ingredients, preparing tofu in oils and creams greatly increases its fat and caloric content. For example, frying tofu in oil boosts its fat and caloric content. In comparison with the 183 calories and 11 grams of fat in 1/2 cup of raw, firm tofu, the same-size serving of fried tofu contains 341 calories and 25.4 grams of fat. Prepared tofu can be fattening even if it is non-fattening in its raw state.
- MayoClinic.com: Counting Calories: Get Back to Weight-Loss Basics
- U.S. Department of Agriculture National Nutrient Database for Standard Reference: Tofu, Raw, Firm, Prepared with Calcium Sulfate
- U.S. Department of Agriculture and U.S. Department of Health and Human Services: Dietary Guidelines for Americans, 2010
- U.S. Department of Agriculture National Nutrient Database for Standard Reference: Tofu, Raw, Regular, Prepared with Calcium Sulfate
- U.S. Department of Agriculture National Nutrient Database for Standard Reference: Tofu, Soft, Prepared with Calcium Sulfate and Magnesium Chloride (Nigari)
- U.S. Department of Agriculture National Nutrient Database for Standard Reference: Tofu, Fried
- The Dietitian's Guide to Vegetarian Diets: Issues and Applications, 3rd Edition; Reed Mangels et al.
Matthew Lee has been writing professionally since 2007. Past and current research projects have explored the effect of a diagnosis of breast cancer on lifestyle and mental health and adherence to lifestyle-based (i.e. nutrition and exercise) and drug therapy treatment programs. He holds a Master of Arts in psychology from Carleton University and is working toward his doctorate in health psychology.