PRACTICAL APPLICATIONS OF SOY IN WEIGHT MAINTENANCE

By Michelle Cardel, PhD, MS, RD, FTOS

Your patient has just reached their goal weight! "Now, how exactly do I keep the weight off?” they may ask. Time and time again, we’ve heard that the key to weight maintenance is to continue to engage in a sustainable and healthy lifestyle. The combination of physical activity, tracking food intake, restorative sleep, and stress management, as well as drinking plenty of water and incorporating foods that are nutrient dense, like soy foods, is one of the best ways to stay healthy.

The Role of Soy in Weight Maintenance

Soy foods can be incorporated into one’s weight maintenance diet in a variety of ways — whether in the form of a traditional soy food, concentrated source of protein, or a modern soy food such as meat and dairy substitutes.

• Protein: The quality of soy protein is greater than that of nearly all other plant proteins¹ and soybeans are higher in protein than other legumes, so it is not surprising that soy foods are excellent sources of this macronutrient. For example, 1 cup of tempeh contains 33 grams of protein,² making up two-thirds of one’s recommended daily intake.³ Similarly, 1 cup of edamame has 18 grams of protein,⁴ while 3 ounces of extra firm tofu has 9 grams.⁵ Eating protein-rich foods can help you feel full,⁶ which may lead to eating fewer calories and preventing weight regain.

• Dairy: Unsweetened, fortified soymilk is a great option to support patients in meeting their dairy recommendations,⁷ while promoting weight maintenance. Compared to a cup of whole milk, which is approximately 150 calories, one cup of unsweetened soymilk is only 80 calories.⁸ Unsweetened soymilk is low in saturated fat and has no added sugars, making it good for weight management. Fortified soymilk also provides vitamin D, calcium, and protein to support muscle and bone health. And importantly, soymilk is the only plant-based milk recommended by the Dietary Guidelines for Americans.

• Vegetables: Soybeans and edamame are nutrient rich and low in calories. Half a cup of shelled edamame has fewer than 100 calories, 9 grams of protein, and 4 grams of fiber.⁴ High-fiber foods digest slowly, keeping you fuller for longer.⁹ This attribute, combined with their protein content, makes them a great choice for weight maintenance.

• Dietary Fat: Although some may be concerned about consuming too much fat during weight maintenance, unsaturated fat is a key nutrient to incorporate, as it helps the body absorb vitamins A, D, E, and K, and provides a source of essential fatty acids. Moreover, it adds to food enjoyment — an essential part of a sustainable diet. Soybean oil, often labeled as vegetable oil, has more unsaturated fat and less saturated fat than butter or coconut oil, making it ideal for weight maintenance and heart health. Soybean oil carries a Food and Drug Administration qualified health claim which suggests that it may reduce the risk of heart disease by lowering blood cholesterol levels.¹⁰ The claim states, “Supportive but not conclusive scientific evidence suggests that eating about 1½ tablespoons (20.5 grams) daily of soybean oil, which contains unsaturated fat, may reduce the risk of coronary heart disease.” It also has a neutral flavor, which works well in a variety of cooking applications like stir fries and pan-fried dishes.

Practical Applications for Patients and Clients

• For breakfast, use unsweetened, fortified soymilk in oatmeal or smoothies to meet dairy needs while keeping saturated fat, added sugar, and calories low.

• If you’re looking for an afternoon snack, heat up a bag of frozen edamame for a protein- and fiber-packed option! Add “everything bagel” seasoning for an extra kick of flavor.

• When cooking, use soybean oil instead of butter or higher fat oils (like coconut oil or palm oil) to cut down on saturated fat.

• Need an appetizer for your party? Try air fried tofu for a crunchy, protein-rich treat that keeps everyone feeling full.

Link to Infographic PDF

REFERENCES

1. Hughes GJ, Ryan DJ, Mukherjea R, Schasteen CS. Protein digestibility-corrected amino acid scores (PDCAAS) for soy protein isolates and concentrate: Criteria for evaluation. J Agric Food Chemistry 2011;59(23):12707-12 doi: 10.1021/jf203220v [published Online First: 2011/10/25].

2. United States Department of Agriculture. Tempeh, cooked. FoodData Central. April 1, 2019. Accessed January 12, 2025. https://fdc.nal.usda.gov/food-details/172467/nutrients

3. United States Department of Health & Human Services. Nutrient Recommendations and Databases. National Institutes of Health Office of Dietary Supplements. Accessed January 12, 2025. https://ods.od.nih.gov/HealthInformation/nutrientrecommendations.aspx

4. United States Department of Agriculture. Edamame shelled soybeans. FoodData Central. December 22, 2022. Accessed January 26, 2025. https://fdc.nal.usda.gov/food-details/2394594/nutrients.

5. United States Department of Agriculture. Extra firm tofu. FoodData Central. December 22, 2022. Accessed January 26, 2025. https://fdc.nal.usda.gov/food-details/2434286/nutrients.

6. Dhillon J, Craig BA, Leidy HJ, et al. The Effects of Increased Protein Intake on Fullness: A Meta-Analysis and Its Limitations. J Acad Nutr Diet. 2016;116(6):968-983. doi:10.1016/j.jand.2016.01.003.

7. U.S. Department of Agriculture, U.S. Department of Health & Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition.; 2020. Accessed July 6, 2023. https://www.dietaryguidelines.gov/.

8. United States Department of Agriculture. Soy milk, unsweetened, plain, shelf stable. FoodData Central. October 28, 2021. https://fdc.nal.usda.gov/food-details/1999630/nutrients.

9. Akhlaghi M. The role of dietary fibers in regulating appetite, an overview of mechanisms and weight consequences. Crit Rev Food Sci Nutr. 2024;64(10):3139-3150. doi:10.1080/10408398.2022.2130160.

10. Food and Drug Administration. Qualified Health Claims: Letters of Enforcement Discretion. Unsaturated fatty acids: Soybean oil and reduced risk of coronary heart disease, July 31, 2017. https://www.fda.gov/food/food-labeling-nutrition/qualified-health-claims-letters-enforcement-discretion.