
- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
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Katherine Zeratsky, R.D., L.D.
Katherine Zeratsky, R.D., L.D.
As a specialty editor for the nutrition and healthy eating guide, Katherine Zeratsky helps you sort through the facts and figures, the fads and the hype to learn more about nutrition and diet.
A Marinette, Wis., native, Katherine is certified in dietetics by the state of Minnesota and the American Dietetic Association. She has been with Mayo Clinic since 1999.
She is active in nutrition-related curriculum and course development in wellness nutrition at Mayo Clinic in Rochester, Minn., and nutrition education related to weight management and practical applications of nutrition-related lifestyle changes.
Other areas of interest include food and nutrition for all life stages, active lifestyles and the culinary arts.
She graduated from the University of Wisconsin-Madison, served a dietetic internship at the University of Iowa Hospitals and Clinics, and worked as a registered dietitian and health risk counselor at ThedaCare of Appleton, Wis., before joining the Mayo Clinic staff.
Weight-loss basics (8)
- Metabolism and weight
- Weight-loss hypnosis: Does it work?
- How is brown fat different from other fat?
- see all in Weight-loss basics
Diet plans (8)
- The Special K diet: Helpful for weight loss?
- Vegetarian diet: Will it help me lose weight?
- Flat Belly Diet: Can it help you lose weight?
- see all in Diet plans
Mayo Clinic diet (1)
- Weight loss: Better to cut calories or exercise more?
Diet and exercise (4)
- Can I use yoga for weight loss?
- Walking: Is it enough for weight loss?
- Negative-calorie foods: Diet gimmick or weight-loss aid?
- see all in Diet and exercise
Question
Body fat: What happens to lost fat?
When you lose weight, where does the lost body fat go?
Answer
from Katherine Zeratsky, R.D., L.D.
To understand the answer, it helps to remember that fat is basically stored energy. Your body converts fat to usable energy for your muscles and other tissues through a series of complex metabolic processes. This causes your fat cells to shrink.
These metabolic activities also generate heat, which helps maintain your body temperature, and waste products. These waste products — water and carbon dioxide — are excreted in your urine and sweat or exhaled from your lungs.
Next questionSlow metabolism: Is it to blame for weight gain?
- Cell metabolism. In: Stanfield CL, et al. Principles of Human Physiology. 4th ed. San Francisco, Calif.: Benjamin Cummings; 2010:88.
- Fundamentals of human energy transfer. In: Katch VL, et al. Essentials of Exercise Physiology. 4th ed. Baltimore, Md.: Lippincott Williams & Wilkins; 2010:175.
- The endocrine system: Regulation of energy metabolism and growth. In: Stanfield CL, et al. Principles of Human Physiology. 4th ed. San Francisco, Calif.: Benjamin Cummings; 2010:607.


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