M.Prasad NaiduMSc Medical Biochemistry, Ph.D,.

ENERGY INRegulation of food intake:HungerSatiation and satietyAppetite

Energy expenditure at rest:BMR - basal metabolic rate: rate of

energy expended at rest (kcal/hr or kcal/day), also called RMR (resting metabolic rate).

Factors that affect BMR (page 257)

Energy expenditure for physical activity:

Depends on the activity duration, type, and intensity

Also affected by body size and fitness level

NEAT is the energy associated with unintentional activities like fidgeting, maintenance of posture, or spontaneous muscle contraction

Energy expenditure to process food: Thermic effect of food (TEF) – the

energy used to digest, absorb, and metabolize energy-yielding food

TEF is lower for fat than for carbohydrate and protein

TEF peaks one hour after eating, and normally dissipates within 5 hours

Accounts for ~10% of total energy expenditure

Estimating energy expenditure:EER – an equation used to estimate

REE based on age, weight, height, and sex

Page 260

Assessing body weight:weight tablesbody mass index (BMI) = weight (kg) height (m2)

As the BMI table shows, healthy weight falls between a BMI of approximately 18.5 and 24.9.

gynoid obesity (pear-shaped figure), more common in women

android obesity (apple-shaped figure), more common in men increases risk of heart disease and

diabetes mellitus

“apple” “pear”

Hereditary and genetic factors Sociocultural influences Age and lifestyle Sex Race and ethnicity Socioeconomic status Employment Psychological factors

Health risks (page 265)Prevalence of overweight and

obesity – it is a worldwide public health problem. We are now seeing an obesity epidemic in children as well as adults.

National Center for Health Statistics suggests nearly 25% of children are overweight or obese

There are now about 5 million obese children in the United States – up by 50% since 1991

A 1999 Survey of Seattle High Schools showed that:

9% of males and 6% of females were overweight

Overweight children and adolescents are more likely to become overweight or obese adults

Type 2 diabetes, high blood lipids, hypertension, early maturation and orthopedic problems also occur with increased frequency in overweight youth

In 2000, the total cost of obesity was estimated to be $117 billion

Most of the cost associated with obesity is due to type 2 diabetes, coronary heart disease, and hypertension

Unfortunately, there is no magic pill, no perfect diet. The simple fact is, if you consume more calories than you burn, you will gain weight

A slow weight loss (1-2 pounds per week) is the best way

To lose 1 pound of fat, you must burn an extra 3500 calories (in one week that = 500 calories per day)

Important Components: Diet composition Physical activity Behavioral change Balancing acceptance and change Support!

A Healthful Eating Plan Involves: Realistic energy

intake Nutritional adequacy Small portions, small

frequent meals Reduced simple sugar

and alcohol intake Adequate water

Contributions to weight loss and maintenance: Direct increases in energy output (muscles

and cardiovascular system) Indirect energy output (elevated BMR) Appetite control Psychological benefits

Note: Spot reducing is not possible.

Behavior modification: the changing of behavior by the manipulation of antecedents (cues or environmental factors that trigger behavior), the behavior itself, and consequences (the penalties or rewards attached to behavior).

Figure 7-7 Food and Activity Diary

• Family• Friends• Weight Loss Support Groups

Adjuncts to treatment Drugs Self-help activities Commercial programs Professional private counselors Surgery: gastric bypass, gastric

banding