The CDC reports that 40.3% of U.S. adults had obesity between August 2021 and August 2023 (National Center for Health Statistics, 2024). While calorie control and physical activity remain cornerstones of weight management, another often-overlooked factor is the thermic effect of food (TEF), the energy used for absorbing, digesting, utilizing, and excreting food’s nutrients. Choosing foods that require more energy can, over time, increase daily calorie expenditure, complementing traditional weight management strategies which include purposefully restricting intake and increasing physical activity.

Practical Implications The TEF represents roughly 10% of total daily energy expenditure in a typical diet (Kahleova et al., 2019). However, the percentage varies by food type: protein has the highest TEF (20-30%), carbohydrates moderate (5-10%), and fats the lowest (0-5%). Whole, fiber-rich foods generally increase the TEF compared to highly processed ones because they require the body to expend more energy for digestion and further processing.

In simple terms, eating 1,000 Calories of broccoli or lean chicken contributes to fewer Calories than eating 1,000 Calories of candy or fried foods. This difference arises because digestion, absorption, utilization, and excretion of these foods themselves require differing amounts of energy, quantified as Calories.

For example, a person consuming a 2000 Calorie diet, with 50% of calories from high-TEF foods (lean protein, fibrous vegetables, beans) might expend roughly 15% of total energy on digestion (roughly 300 Calories), whereas someone consuming mostly low-TEF foods (refined carbs, high-fat processed foods) might expend only about 7.5% (about 150 Calories). This 150 Calorie difference equates to about 19 minutes of moderate cycling (approximately 8 Cals/min).

Over time, the difference is significant. This 150 Calorie daily added expenditure, simply do the the differences in TEF, equals about 4,500 Calories per month, roughly 1.3 pounds of body fat.

Foods with a High Thermic Effect High-TEF from protein sources include chicken breast, fish, eggs, tofu, and legumes, Fiber-rich foods with a high TEF include beans, lentils, oats, quinoa, vegetables, and fruits with skin. And minimally processed foods with notably high TEFs include whole grains and unrefined plant foods.

Low-TEF foods include sugary snacks, candy, refined grains, fried foods, and high-fat ultra-processed meals. Replacing these with high-TEF alternatives not only raises metabolism slightly but also increases satiety and nutrient density.

Beyond Calories: Additional Benefits of High-TEF Foods Diets rich in fiber and lean protein improve gut health by supporting beneficial microbiota and regular digestion. Soluble fiber from oats, beans, and fruit lowers LDL cholesterol (the cholesterol contributing to arterial plaque). Additionally, focusing on whole foods displaces intake of ultra-processed and high saturated fat items linked to obesity and heart disease. Because protein and fiber slow digestion, they enhance fullness and help control appetite. Protein also preserves lean muscle, maintaining resting metabolism during weight loss.

Summary and Conclusion Strategically choosing foods with a higher TEF, such as lean proteins, legumes, whole grains, and vegetables can increase energy expenditure by roughly 150 kcal per day, the equivalent of approximately 20 minutes of moderate cycling. Over time, this difference can contribute to meaningful weight control.

Prioritizing high-TEF, fiber-rich, minimally processed foods helps improve satiety, cardiovascular health, and digestion, while increasing the body’s long-term energy expenditure. A registered dietitian who specializes in weight loss can work with client’s food preferences and the concept of different TEFs of foods to establish delicious, satisfying, sustainable life-long intake patterns that is not only more rewarding, it can actually increase total daily energy expenditure. Further, the dietitian can help develop a realistic exercise or activity plan that can further contribute to overall health and weight loss goals.

About the Author

Patrick Traynor, PhD, MPH, RD, CSOWM, CPT, is a registered dietitian and founder of MNT Scientific, LLC (MNTScientific.com), an insurance-based nutrition practice serving South Lake Tahoe, CA; Minden, NV; and Ashland, OR. He holds the Interdisciplinary Specialist Certification in Obesity and Weight Management (CSOWM) from the Commission on Dietetic Registration. Virtual appointments are available in-office or via telehealth. For inquiries or appointments, visit MNTScientific.com, dial (530)429-7363, or email securefoodphoto@mntscientific.hush.com.