1. Energy Balance and Obesity
Jamie Pope, Steven Nizielski, and Alison McCook
NUTRITION
for a Changing World
FIRST EDITION
Chapter 15
Energy Balance and Obesity
The Sitting Disease
© 2016 by W. H. Freeman and Company & Scientific American

2. Chapter 15
Objectives
List the health consequences associated with obesity, and describe how excess body fat increases the risk of developing these conditions
Describe the concept of energy balance
Identify and describe the components of total energy expenditure
Describe factors that affect basal metabolic rate
Describe activities that are examples of nonexercise activity thermogenesis (NEAT)
Describe factors that contribute to the development of obesity
Use body mass index and waist circumference to evaluate someone’s risk of chronic disease
Describe methods for determining body composition
Discuss strategies for successful weight loss and maintenance

3. The Sitting Disease Obesity epidemic Obesity Overweight
Complex disease influenced by multiple factors
Genetics
Environment
Behavior
Obesity
Over one-third of U.S. adults in 2014
Overweight
Over two-thirds of U.S. adults in 2014
“Genetics loads the gun and environment pulls the trigger.” Genetics determine a person’s susceptibility to obesity but the environmental changes promote low levels of physical activity and the consumption of energy-dense diets promote weight gain in genetically susceptible individuals.

4. The Sitting Disease
“Genetics loads the gun and environment pulls the trigger.” Genetics determine a person’s susceptibility to obesity but the environmental changes promote low levels of physical activity and the consumption of energy-dense diets promote weight gain in genetically susceptible individuals.

6. Energy In, Energy Out Energy Calorie Energy in Energy out
Capacity to do work
Calorie
Energy required to raise 1 g of water 1°C
Kcal is the energy required to raise 1 kg of water 1°C
Energy in
Energy we consume
Energy out
Energy we burn

7. Energy Balance

8. Excess Body Fat
Enlarged fat cells produce excess hormones and hormone-like messengers
Hormones cause low-grade inflammation
Adipose tissue (body fat) secretes hormones, which leads to low-grade chronic inflammation and increased risk of chronic disease.

9. Biology of Hunger Short-term system Long-term system
Mediated by hormones
Ghrelin
Mediated by stomach pressure
Regulates hunger and satiety
Long-term system
Leptin
Adjusts food intake and energy expenditure
Maintains adequate fat stores

10. Hormones in Energy Balance
Ghrelin
Produced in the stomach
Stimulates hunger
Leptin
Produced by adipose tissue
Suppresses hunger

11. Factors Affecting Fullness
Satiation
Sense of fullness
Leads to termination of a meal
Satiety
Feeling the effect of a meal
Lacking interest in food
Gastric distention
Gut peptides

12. Hunger and Appetite Hunger Appetite Is a biological impulse
Liking or wanting of food
Is a product of sensory stimuli and perceived pleasure
Affected by the “toxic food environment”

13. Energy Expenditure Total energy expenditure (TEE) Basal metabolism
Thermic effect of food (TEF)
Activity energy expenditure (AEE)

14. Basal Metabolic Rate (BMR)
Factors that affect BMR
Fat-free mass (FFM)
Age
Sex
Growth
Hormones
Starvation
Illness
Pregnancy and lactation
Ethnicity
Caffeine
Smoking
Sleep
Fat-free mass is the total body mass minus fat mass (adipose tissue). Fat-free mass is the greatest factor impacting BMR. The higher a person’s FFM, the greater their BMR.

15. Fat-free mass is the total body mass minus fat mass (adipose tissue)
Fat-free mass is the total body mass minus fat mass (adipose tissue). Fat-free mass is the greatest factor impacting BMR. The higher a person’s FFM, the greater their BMR.

16. Activity Energy Expenditure
Exercise
Nonexercise activity thermogenesis (NEAT)
Activities of daily living
Levine found that obese people sit more then lean people; they had less NEAT.

17. Lifestyle and Energy Balance

18. Lifestyle and Energy Balance

19. Lifestyle and Energy Balance

20. Lifestyle and Energy Balance

21. Lifestyle and Energy Balance

22. Lifestyle and Energy Balance

23. What Is a Healthy Body Weight?
Body mass index (BMI)
body weight (kg)/height2 (m2)

24. Body Mass Index

25. Waist Circumference Estimator of abdominal obesity
Waist circumference exceeds 35 inches in women
Waist circumference exceeds 40 inches in men
Visceral fat is an independent health risk
Cardiovascular disease
Type 2 diabetes
Premature all-cause mortality

26. Waist Circumference

27. Analyzing Body Composition
Dual-Energy X-Ray Absorptiometry (DEXA)
Underwater Weighing (Hydrodensitometry)
Bioelectrical Impedance
Skinfold Thickness
Air Displacement

28. Weight-Loss Recommendations
Weight-loss recommended for anyone with a BMI of 30 or greater and anyone overweight with two or more other risk factors
Elevated waist circumference
Cardiovascular disease
Family history of cardiovascular disease
Smoking
Hypertension
Diabetes
Physical inactivity
Age (men 45 years or older; women 55 years or older or postmenopausal)

29. Weight Loss
Modest reduction of body weight results in health improvements
Losing and maintaining 5% to 10% of body weight can reduce risk of chronic disease and all-cause mortality by about 50%

30. Surgical Approaches to Weight Loss
For BMI of 40 or above or BMI of 35 or above with additional risk factors
Benefit should be greater than significant risk

31. Dietary and Lifestyle Approaches to Weight Loss
Effective approaches
Increase physical activity
Reduce calorie intake with nutrient-dense foods
Eat moderately low-fat diet (less than 30% of calories)
Eat moderately high-protein diet (25% to 30% of calories)
Include plenty of non-starchy vegetables, fruit, whole grains with high fiber, and lean sources of protein

32. Determine Your Estimated Energy Requirement
Estimate your physical activity level (PA).
Convert your body weight in pounds to kilograms by dividing by 2.2.
Convert your height in inches to meters by multiplying by 2.54 (to convert to centimeters) and then dividing by 100 to convert to meters.
Enter your values into the appropriate equation below for people 19 years and older: Men: EER = (662 − (9.53 x age) + PA x (15.91 x weight in kg) + (539.6 x height in m) Women: EER = (354 − (6.91 x age) + PA x (9.36 x weight in kg) + (726 x height in m)

33. Weight-Loss Maintenance
National Weight Control Registry (NWCR)
Common strategies of successful weight-loss maintenance
Maintaining a lower-fat, reduced-calorie eating plan
Eating breakfast
Weighing self at least once a week
Watching fewer than 10 hours of television per week
Exercising on average about one hour per day

35. A Moratorium on the Chair
Increase NEAT
“Get out of the chair”
Move more

36. Summary
Obesity is at epidemic proportions in the United State, with more than two-thirds of adults classified as overweight or obese
Energy, the capacity to do work, is required to perform all functions necessary to sustain life and is obtained through the breakdown of carbohydrates, fats, proteins, and alcohol in food
A calorie, a unit of measure, is defined as the energy required to raise 1 gram of water 1°C. The energy in food is commonly measured in units of kilocalories (1,000 calories). A kilocalorie (kcal) is the energy required to raise 1 kilogram of water 1°C.
Energy balance is a reflection of energy intake versus expenditure. Although there are many factors that contribute to the development of obesity, fundamentally it results from chronic positive energy balance. Negative energy balance is necessary for weight loss
Obesity increases the risk of multiple chronic diseases and premature death. Hormonal changes associated with excess body fat cause a low-grade chronic inflammation throughout the body that has adverse health effects

37. Summary (Cont’d)
Energy balance and food intake are regulated through a short-term system and a long-term system. The short-term system is mediated by hormones and stomach pressure and is responsible for triggering hunger and satiety during individual meals. The long-term system, mediated by a different set of hormones, adjusts food intake and energy expenditure to maintain adequate fat stores
Satiation is the sense of fullness we feel while eating and leads to the termination of a meal. Satiety is the effect that the meal has on our interest in food and hunger levels after and between meals
The hormone ghrelin stimulates hunger by activating specific neurons in the brain. Circulating levels of ghrelin in the blood increase just before meals and decrease after eating

38. Summary (Cont’d)
The hormone leptin is produced primarily by adipose (fat) tissue and has a role in long-term energy balance. Its circulating concentration is closely associated with total body fat
Hunger is the biological impulse that drives us to seek out food and consume it to meet our energy needs. Appetite is a desire for or liking of food for reasons other than, or in addition to, hunger
Total energy expenditure (TEE) is composed of basal metabolism, the thermic effect of food, and activity energy expenditure (AEE)

39. Summary (Cont’d)
Basal metabolism is the energy expenditure required to maintain the essential functions that sustain life. It accounts for about 60% of TEE in a typical sedentary individual, with most variation from person to person accounted for by differences in fat-free mass
Thermic effect of food (TEF) is the energy needed to digest, absorb, and metabolize nutrients in our food. TEF is generally equivalent to 10% of the energy content of the food ingested and does not vary greatly between people
Activity energy expenditure is the amount of energy individuals expend in physical activity per day and is the most variable component of TEE
Body mass index (BMI) is an indirect measure of body fat, calculated from a person’s weight and height. “Underweight,” “normal,” “overweight,” and “obese” are labels for ranges of body weight on the BMI scale

40. Summary (Cont’d)
The greater the BMI, the higher the risk of premature mortality and the risk of obesity-associated diseases. A BMI in the underweight range is also associated with increased premature mortality
Waist circumference indicates body fat distribution and the presence of excess visceral fat, which has been shown to be an independent health risk
Body composition can be measured in a variety of ways, including skinfold thickness with calipers, underwater weighing, air displacement, bioelectrical impedance, and dual-energy x-ray absorptiometry

41. Summary (Cont’d)
Weight loss, including dietary modifications and increased physical activity, is recommended for anyone with a BMI of 30 or higher or those who are overweight and have two or more risk factors, or have an elevated waist circumference. For those with extreme obesity (a BMI of at least 40 or a BMI of at least 35 with additional risk factors), weight-loss (bariatric) surgery may be recommended
Modest weight loss and maintenance (5% to 10% of body weight) can improve health, as well as reduce the risk of chronic diseases and premature death
Healthy weight-loss plans maximize nutrient density while reducing calorie intake; increase physical activity; incorporate behavioral strategies to enhance compliance; address individual health concerns; and consider maintenance of a lower body weight