1. Weight Management: Nutrition & Physical Activity Part I

2. Energy In: Influences on Hunger  Hunger  Physiological response to nerve signals and chemical messengers  Hypothalamus: control center in brain  Many influences!  Satiation – signal stop eating  Satiety – satisfaction between meals; signal not to eat

3. Energy In: Food Composition

4. Hunger vs. Appetite: Internal vs. External Signals  Overriding hunger and satiety  Stress eating  External cues  Time of day, availability, sight, taste of food  Environmental influences  Examples?  Disordered eating  Psychological influences and beliefs

5. Sustaining Satiation and Satiety  Nutrient composition  Protein is most satiating  Low-energy density foods are more satiating  Why?  High-fiber foods are more satiating  Why?  High-fat foods – strong satiety signals

6. Energy Out  We utilize energy from food for moving body, fueling chemical reactions, functioning of organs  These functions generate heat  Thermogenesis  Basal metabolism  Physical activity  Food consumption: digestion & absorption  Adaptation

7. Components of Energy Expenditure – Basal Metabolism  About two-thirds of energy expended in a day  Metabolic activities  All basic processes of life  Basal metabolic rate (BMR)  Varies greatly from one individual to the next!  Major influence that we can control: amount of lean tissue

8. Components of Energy Expenditure – Basal Metabolism

9. Components of Energy Expenditure – Physical Activity  Voluntary movement of skeletal muscles  Most variable component of energy expenditure  Amount of energy needed  Muscle mass  Body weight  Activity  Amount expended depends on frequency, intensity, and duration of activity

10. Components of Energy Expenditure – Thermic Effect of Food  Acceleration of GI tract functioning in response to food presence  Releases heat  Approximately 10 percent of energy intake

11. Components of Energy Expenditure – Adaptive Thermogenesis  Adapt to dramatically changing circumstances  Examples: intense physical conditioning, extreme cold, trauma, stress  Extra work done by body  Amount expended is extremely variable  Not included in energy requirement calculations

12. Fat Cell Metabolism  Lipoprotein lipase (LPL) activity  Storage of triglycerides  Obese people vs. lean people  Activity in varying body regions  Men vs. women  Enzyme activity releasing and breaking down fat: individual differences  LPL activity increases after weight loss

13. Causes of Overweight & Obesity – Genetics & Epigenetics  Causative role of genetics  Genetic influences do seem to be involved  Genetics may determine predisposition to obesity  Epigenetics  Gene expression influenced by:  Diet  Physical activity  Satiety and energy balance

14. Causes of Overweight & Obesity – Environment  Encountered daily circumstances  Interaction between environment and genetics (epigenetics)  Overeating  Present and past eating and activity patterns influence current body weight  Availability  Serving sizes  Restaurant food

15. Causes of Overweight & Obesity – Environment  Physical inactivity  Life requires little exertion  Modern technology  Inactivity contributes to weight gain and poor health  Sedentary activities and weight gain  DRI for prevention of weight gain  60 minutes of moderate activity every day

16. Problems of Overweight and Obesity – Health Risks  Three indicators  BMI  Waist circumference  Disease risk profile  Factors taken into account  Would weight loss be beneficial?  Health status  Motivation

17. Problems of Overweight and Obesity – Health Risks  Overweight in good health  Sometimes health is not the motivation for weight loss  Obese or overweight with risk factors  Two or more risk factors: weight loss recommended  Obese or overweight with life-threatening condition  Clear recommendation to lose weight

18. Problems of Overweight and Obesity – Perceptions & Prejudices  Most obese people do not successfully lose weight and maintain the loss  Social consequences  Jobs, school, and in social situations  Psychological problems  Embarrassment  Other feelings

19. Problems of Overweight and Obesity – Perceptions & Prejudices

20. Problems of Overweight and Obesity – Dangerous Interventions  Intervention dangers  Diet books and weight-loss programs  Little success with weight loss maintenance  Fad diets  Weight-loss products  Herbal products  Laws for dietary supplements  Other gimmicks

21. Weight Loss Strategies  Successful strategies  Small changes  Moderate losses  Reasonable goals  Reasonable rate of weight loss  Benefits of modest weight loss  Incorporation of healthy eating and physical activity

22. Weight Loss Strategies – Eating Plans  Be realistic about energy intake  Create an energy deficit, but  Avoid restrictive eating  Avoid rapid weight loss  Goal: nutritional adequacy without excess  Deficit of 500 to 1000 kcalories per day  Greatly assisted by physical activity!!  Breakfast frequency  Inversely related to obesity

23. Weight Loss Strategies – Eating Plans  Nutritional adequacy  Minimum of 1200-1500 kcalories a day  Eat small portions  Eat less calorie-dense food at each meal  Feel satisfied, not stuffed: Hara hachi bu  Lower energy density  Price of food vs. health cost

24. Weight Loss Strategies – Eating Plans  Remember water  Assistance with weight management  Focus on fiber-rich foods  Low in energy and high in nutrients  Require effort to eat  Speed of food consumption  To fat or not to fat?  Energy density vs. satiety  See study!

25. Weight Loss Strategies – Eating Plans  Select carbohydrates carefully  Whole vs. refined  Quality and quantity matter  Artificial sweeteners  Impact on energy intake  Watch for empty kcalories  Fat, sugar, and alcohol

26. Importance of Physical Activity  Best approach to weight management  Moderate physical activity plus activities of daily life  Combination of diet and physical activity  Lose more fat  Retain more muscle  Regain less weight  Reduction of abdominal fat  Especially resistance and HIIT  Cortisol connection

27. Weight Loss Strategies – Physical Activity

28. Physical Activity  Body composition  Fat decreases and lean body mass increases  Decreased abdominal fat=decreased disease risk  Appetite control  Delayed appetite  Reduces eating in absence of hunger  Emotional/stress eating  Another cortisol connection!

29. Weight Loss Strategies – Physical Activity  Psychological benefits  Self-esteem  Stress management  Choosing activities  Ones you enjoy & are willing to do regularly  Increase energy-expending daily activities  Spot reducing?

30. Weight Maintenance  Successful weight loss  Plateau  Appropriate goal at this point?  Changing up physical activities  Sustained weight loss  Takes more effort to prevent regain than to prevent initial gain  Increased lean body mass helps

31. Underweight  Affects no more than 5% of U.S. adults  Weight gain is a matter of health  Individual matter  Weight gain may be difficult  Demand for energy contributes to underweight  Physical activity  Growth and development

32. Weight-Gain Strategies  Key diet planning strategies  Adequacy and balance  Energy-dense foods  Regular meals daily  Large portions  Extra snacks  Liquid meals (shakes)