Lecture 18: Weight Management. Celebrity Role Models? Celebrity Role Models? Nutrition 150 Shallin Busch, Ph.D.

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1 Increasing Prevalence of Obesity (BMI _ >30) among U.S. Adults Lecture 18: Weight Management 1991: Only four states had obesity rates greater than 15 percent. 1996: Over half of the states had obesity rates greater than 15 percent. Key: No Data <10% 10% 14% 15% 19% 20% 24% _ >25% Nutrition 150 Shallin Busch, Ph.D. 2001: Only one state had an obesity rate below 15 percent, most had obesity rates greater than 20 percent and one had an obesity rate greater than 25 percent. Celebrity Role Models? Celebrity Role Models? Name Height Weight (lbs) BMI Name Height Weight (lbs) BMI Twiggy Lawson Brad Pitt Paris Hilton Matt Damon Gwenyth Paltrow George Clooney Eva Longoria Justine Timberlake Jennifer Lopez Tyra Banks

2 The Declining Weight of Miss America The Body and its Weight BMI Fat Cell development Storing fat Set-point theory Genetics Year During growth, fat cells increase in number. When energy intake exceeds expenditure, fat cells increase in size. Fat Cell Development When fat cells have enlarged and energy intake continues to exceed energy expenditure, fat cells increase in number again. With fat loss, the size of the fat cells shrinks, but not the number. Fat cells are capable of increasing their size by 20-fold and their number by several thousandfold. Lipoprotein Lipase Enzyme that breaks down triglycerides Necessary for fats to enter cells High LPL activity makes fat storage very efficient Regulated, in part, by hormones Where activity is high in the body helps determine where fat is deposited After weight loss, LPL activity increases Can make it difficult to keep weight off

3 Set-Point Theory The body regulates important internal variables to be fairly stable (temperature, ph, blood glucose) In terms of weight, set-point theory predicts that the body tends to maintain a certain weight by means of its own internal controls With weight loss or gain, the body can and will adjust metabolism to restore original weight Set-Point Theory Set point seems to be influenced by your weight as a child, if underweight, healthy weight, overweight or obese Set point can be altered with long-term changes in diet and activity patterns Genetics and Weight Genes do NOT cause you to be obese Genes can determine a person s susceptibility for obesity Genetics and Weight Genetics can influence the body s set point Genetics can influence production of hormones and other chemicals related to energy storage and use

4 Physiology of Energy Balance: Leptin Leptin Deficiency Without leptin, this mouse weighs almost three times as much as a normal mouse. With leptin treatment, this mouse lost a significant amount of weight, but still weighs almost one and a half times as much as a normal mouse. Hormone made by fat cells Suppresses appetite Increases energy expenditure Obese people may be insensitive or resistant to leptin Physiology of Energy Balance: Ghrelin Hormone made by stomach cells Stimulates appetite Promotes efficient energy storage Declines after eating Levels don t decline after eating in obese people Levels are high in people who are underweight Without leptin, this mouse weighs almost three times as much as a normal mouse. The Brain and Energy Balance: Neuropeptide Y A brain chemical that causes carbohydrate cravings, initiates eating, decreases energy expenditure, and increases fat storage

5 Balancing Physiology, Mind, and the Environment Food advertisements are geared to increase our appetite Social settings Lifestyle Why People Change Weight Passive Weight Change Because they change their lifestyle Because they change their relationship with food Because they change their feelings about themselves Why People Change Weight Active Weight Change If they are unhealthy If they are unhappy with their current weight Overweight? Overweight and in good health Obese/overweight with risk factors Obese/overweight with lifethreatening condition(s)

6 Problems with Weight Loss Goals are often unreasonable Unmet goals can be disappointing Diet plans can be hard to maintain Medication can be dangerous Procedures are very invasive and potentially problematic Reasonable Weight Loss? Between lbs per week If you average 1 lb loss per week Lose about 4 lbs per month Lose 25 lbs in six months! Weight loss usually tapers after 6 months 1 lb = 3500 cal, so need cut out 500 cal on each day of the week 220 Reasonable Weight Goals vs. Expectations The Psychology of Weight Cycling 200 Reasonable goal weight (5 to 10% below initial weight) I am fat and unhappy. Weight (pounds) Actual weight Disappointing weight Acceptable weight Happy weight Dream weight I lose a little weight, but then regain it (and sometimes more). I want to be happy Suggested healthy weight range I try too hard to reach an unrealistic goal. If I lose weight, I will be happy. 0 Time (year) 1

7 Healthy Dieting Set reasonable goals Be reasonable about energy intake Energy Density Selecting grapes with their high water content instead of raisins increases the volume and cuts the energy intake in half. Emphasize nutritional adequacy Eat small portions Lower energy density Focus on complex carbohydrates Even at the same weight and similar serving sizes, the fiber-rich broccoli delivers twice the fiber of the potatoes for about onefourth the energy. Choose fats sensibly Drink plenty of water Understand your food intake and relationship with food By selecting the water-packed tuna (on the right), a person can enjoy the same amount for fewer kcalories. Food Record Figure 9-8 Page 299 Why do health professionals recommend eating slowly when trying to lose weight? The entries in a food record should include the times and places of meal and snacks, the types and amounts of foods eaten, and a description of the individual s feelings when eating. The diary should also record physical activities: the kind, the intensity level, the duration, and the person s feelings about them.

8 Beware of over-the-counter supplements! Millions of people use them 10% are a healthy weight Only benzocaine has been approved by the FDA Some are banned (Ephedrine) Many have adverse effects Many are non-effective Medications for Weight Loss Subutramine (Meridia): suppresses the appetite Side effects: dry mouth, headaches, constipation, rapid heart rate, high blood pressure Orlistat: Inhibits the activity of pancreatic lipase in the GI tract, blocking fat digestion and absorption by 30% Side effects: gas, frequent bowel movements, reduced absorption of fat-soluble vitamins

9 Surgical Options Stomach Surgeries When obesity is severe (BMI >35) Health risks from obesity are extreme Individuals have not been able to lose weight with energy restriction and exercise Stomach Surgeries What about Liposuction? Cosmetic procedure Not recommended to treat obesity Removes fat cells from localized area Risk of blood clots, skin and nerve damage, perforation injuries, deformation of area around procedure

10 Healthy Weight Gain Body needs time to adapt to higher food intake Reasonable goal is gain of 1 lb a month Energy dense foods Regular meals every day Large portions Extra snacks Juice and milk Exercising to build muscles If exercising, goal of cal/day extra