Chapter Eight- Part Two

Weight Control

Food & Nutritional Health NUT SCI –242Karen 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 cellsGlucose normally used for the

nervous system is now used to spare muscle and lean tissue

E. Dangers Associated with Fasting

Ketosis is harmful to bodySome 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 imbalanceRisk 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 400-700 calories per dayDangers associated with: (table 8-5)

– Dehydration– Weakness/fatigue– Ketosis– Kidney infection– Decreased metabolic rate

Cont’d

Menstrual irregularityLoss of lean body tissueSudden 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 DiureticsHerbal 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 modificationWeight 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 levelDiet should be nutritionally adequateDiet should contain foods that are

enjoyable, available, affordableEat regularly

Cont’d

Use positive imagingDon’t weigh more than once every

week or twoPlan aheadUse positive reinforcementBe honest with yourselfBe responsible for yourselfMaintain 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