- 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 (6)
- Slow metabolism: Is it to blame for weight gain?
- Breakfast: How does it help weight control?
- Fast weight loss: What's wrong with it?
- see all in Weight-loss basics
Diet plans (9)
- Flat Belly Diet: Can it help you lose weight?
- HCG diet: Is it safe and effective?
- Dieting? Beware of liquid calories
- see all in Diet plans
Mayo Clinic diet (1)
- Weight loss: Better to cut calories or exercise more?
Diet and exercise (4)
- Weight loss: Better to cut calories or exercise more?
- Can I use yoga for weight loss?
- Negative calorie foods: Diet gimmick or weight-loss aid?
- see all in Diet and exercise
Diet pills, supplements and surgery (14)
- Phentermine for weight loss: Can it help?
- Hoodia: Does this dietary supplement help weight loss?
- Water retention: Are there any natural diuretics?
- see all in Diet pills, supplements and surgery
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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.
Body fat breaks down during a series of complex metabolic processes.
When you burn more calories than you consume, your body uses fat (triglycerides) for energy. This causes your fat cells to shrink. In turn, triglycerides are broken down into two different substances — glycerol and fatty acids — which are absorbed into your liver, kidneys and muscle tissue. From there, the glycerol and fatty acids are further broken down by chemical processes that ultimately produce energy for your body.
These activities generate heat, which helps maintain your body temperature. The resulting waste products — water and carbon dioxide — are excreted in urine and sweat or exhaled from your lungs.
Next questionMetabolism: What's the best way to boost it?
- Stanfield CL, et al. Cell metabolism. In: Stanfield CL, et al. Principles of Human Physiology. 3rd ed. San Francisco, Calif.: Pearson/Benjamin Cummings; 2008:88.
- McArdle WD. Overweight, obesity and weight control. In McArdle WD. Exercise Physiology. 6th ed. Philadelphia, Pa.: Lippincott Williams & Wilkins; 2007:852.
- Stanfield CL, et al. The endocrine system: Regulation of energy metabolism and growth. In: Stanfield CL, et al. Principles of Human Physiology. 3rd ed. San Francisco, Calif.: Pearson/Benjamin Cummings; 2008:607.
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