11.18.13 kin 110 class notestest on Friday, lectures 15/16-30, in totman gym- 98-99% of people who lose weight on a weight loss diet will regain it- what about the 1-2% who do lose weight and maintain it?- National weight control registry: “list” of people who lost 20 lbs or more, keptit off for > 6 monthso Currently over 6000 people registeredo What are the secrets to success? 1. A low calorie diet and low fat- 1800 calories per day 2. A high amount of physical activity- “report doing close to an hour a day of physical activity”- “that seems to be a key characteristic for maintenance ofweight loss”- considerable physical activity is necessary for weight loss maintenanceo change in weight (kg) vs time (months)o three dif. groups: < 150 min/week, >150 min week, > 200 min/weeko less than 150, regained half of weight losto only group to maintain weight loss: >200 min/weeko the recommendation isn’t enough to maintain weight loss in most peopleo exercise recommendations are too low for Americanso need more than 30 mins per day every day- what makes exercise so effective?o 1. Energy expenditure; 60’ moderate intensity exercise 500-750 kcalso sitting = 60 kcals abouto equipment usually tells you how many kcals you are burning how accurate is that? not that far off, can’t be totally unrealistic, overestimate by about 20% higher than reality this is because the products are all competing with each othero if input weight and track heart rate, 10% off overestimate people trying to carefully track calories taken in/expenditure this can throw them offo iphone app may be slightly more accurate – has weight- 2. Post-exercise increase in metabolic rateo RMR elevated after exercise, 2-24 hours Intensity – aerobic activity (less intensity) Duration – how long you exercised foro How much? Even if RMR elevated by 5% 80-90 calories- 3. Maintenance of muscle mass. Active tissue that expends a lot of calorieso Sleeping metabolic rate vs. Fat free body masso Positive slopeo Starts around 2500 g fat free body mass- Exercise opposes effects of low leptin to reduce energy expenditureo Less leptin – less signal to hypothalamus for satietyo Exercise opposes that, hypothalamus is still sensitiveo Better able to maintain weight losso Allows people to maintain energy deficit while still eating a reasonable # of kcals- Time magazine articleo Person on treadmill with cupcake on mindo Will gain back calories burned latero Social media = exercise is useless for weight loss, this is good/bad?o People trying to promote exercise has been undone by one articleo Barry braun- went around the world talking about exercise!- Keys to think about:o 1. Talking about effects of exercise on appetite short term or long term? Days/weeks/monthso Body fato 2. Meal to meal energy intake at each meal interval between meals size of meals all of these could be important as well- tonic: energy in and out integrated over months, yearso leptin and insulino changes are going to be important in weight regulationo long term- episonic: meal size, meal to meal intervalso initiation of meal (hunger)o termination of meal (satiety)o under control of different componentso ^^regulated very differently- satietyo incretins, gastrointestinal hormones that feedback on insulin production and satiety in the braino GLP1o PYYo GIPo CCKo Stomach & small intestineo Class of hormones related to satietyo Somehow change how full you feel- Ghrelino Induces hungero Time over 24 hours, peaks at breakfast, lunch, dinner, after dinner…o Cause and effect relationshipo Infuse ghrelin into blood and it causes them to become hungryo Affected by exercise- During exercise:o Suppression of appetiteo Exercise stress (epinephrine, increase in body temperature, in cold – less suppression of appetite, people who swim not as much suppression)o Vertical motion – people who jump rope have more suppression of appetite- EIA inhibition of appetite is transient (short term)o Longer term:o 1. No compensation = don’t eat any more kcals lose weighto 2. Partial compensation = eat some more kcals, slowly lose weighto 3. Full compensation = eat back all kcals no weight loss- interestingly, exercise to maintain weight loss may be more effective in men than in womeno women might replace kcals to maintain body weighto why?- Last, physical activity maintains health and decrease risk for diseaseso Lean, normal, obeseo Fit vs.
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