Chapter Eight- Part Two Weight Control Food & Nutritional Health NUT SCI –242 Karen Lacey, MS, RD, CD © Spring 2005

Weight Gain & Loss A. Changes in body weight are influenced by different components Fat Fluid Bone minerals Lean tissues (muscles, organs) Type of tissue gained or lost dependent upon method used.

B. Weight Gain Any energy yielding nutrient can make a person fat (carbs, fat or protein) Energy is stored in 2 forms: – Glycogen – Fat – Protein eaten in excess of need is converted to fat and can not be recovered for later use as protein.

C. Weight Loss & Fasting The body draws from its stored glycogen & fat when a person stops eating If the fast continues, the body uses its lean tissues for fuel – Rapid weight loss is due to a loss of water and the body is depleting its own protein for fuel – Glycogen & protein contain half as many calories per pound as fat – 3-4 pounds of water are lost with each pound of protein

Cont’d Vital organs can be burned as fuel if severe weight loss continues Death results when all the body fat is gone or when half the lean tissue is gone The body tries to adapt to fasting and converts fat into a form the nervous system can use – Ketosis occurs

D.Ketosis Body breaks down fats, combines them to make ketone bodies Ketone bodies circulate in blood Energy from ketone bodies is usable by brain cells Glucose normally used for the nervous system is now used to spare muscle and lean tissue

E. Dangers Associated with Fasting Ketosis is harmful to body Some ketone bodies are made of acids and when present in excess may cause and acid-base imbalance Lean tissue is being used to supply glucose to nervous system Body’s metabolic rate slows down to conserve energy

F. High-Protein, Low-Carb Diets Information about low-carb diets is often misleading Physiological dangers associated with low-carb diets – Ketosis – High blood cholesterol – Hypoglycemia

Cont’d Mineral imbalance Risk of kidney damage – Nitrogen lost from glucose conversion of protein must be excreted – Excessive nitrogen excretion can be hard on the kidneys

G. Very Low-Calorie Diets Provide calories per day Dangers associated with: (table 8-5) – Dehydration – Weakness/fatigue – Ketosis – Kidney infection – Decreased metabolic rate

Cont’d Menstrual irregularity Loss of lean body tissue Sudden death

H. Drugs & Weight Loss Stimulants – Reduce appetite temporarily – Trigger stress response – Usually followed by weight gain when pills are stopped Others – Stimulate serotonin release – Curbs appetite/ reduces food intake – Lipase inhibitors

Cont’d Over-the-Counter appetite suppressants Fiber pills Diuretics Herbal supplements

I. Surgery & Weight Loss Bypass surgery to reduce absorption – Removes or disconnects a portion of the small intestine – Dangerous – Results are often disappointing – Seldom works in the long run

Cont’d Stapling the stomach to reduce capacity – May damage tissue – Scar tissue is formed – Staples can be pulled loose Cosmetic surgery

J. Weight Loss Strategies Important to use a sensible approach – Combination of diet, exercise and behavior modification Weight maintenance is the real goal, not merely weight loss

Cont’d A. Never say diet – Chronic problem needs long-term solution – Gradually develop healthful habits – Examine attitudes

B. Meal planning Select a plan that can be adopted for life Choose an appropriate calorie level Diet should be nutritionally adequate Diet should contain foods that are enjoyable, available, affordable Eat regularly

Cont’d Use positive imaging Don’t weigh more than once every week or two Plan ahead Use positive reinforcement Be honest with yourself Be responsible for yourself Maintain self-esteem

C. Exercise Regular exercise contributes to cardiovascular fitness For best results, exercise should be easy-paced and moderate to long in duration Regular exercise alters body composition toward lean – Results in raised metabolic rate