News From The American College of Sports Medicine on Your Weight!
It is the perfect time of the year – January 2015 – for great news on how to lose weight. Here is the real scoop on weight-related research from the American College of Sports Medicine (ACSM). Valuable info for soccer players, college students as well as coaches and parents.
Exercise is medicine.
Exercise is medicine.was a key message highlighted at the 2014 Annual Meeting of the American College of Sports Medicine. With two-thirds of Americans either overweight or obese, and with healthcare costs (to say nothing of quality-of-life costs) staggeringly high, we need to figure out how to turn this ship around. Athletes need to monitor their weight as well. With new research by ACSM related to diet, exercise, weight, and health, here is the info you need to remind you that wise food & exercise programs are far better than taking medicine.
- To lose weight, you need to create an energy deficit. But is it true the less you eat, the more weight you will lose?
No. A big slashing of calories poorly predicts how much weight you will lose because your body adapts to perceived “famine” conditions by conserving energy.
In a three-month study, young, healthy women were given a diet to lose weight. One diet had a moderate (-400) calorie deficit; this group lost six pounds in 3 months. The other diet had a severe (-850) calorie deficit; that group lost only 8 pounds. This was far less than predicted and related to a drop in resting metabolic rate. The body’s ability to conserve energy is quite powerful! If you want to lose weight, plan to chip off just a few hundred calories at the end of the day, rather than starve yourself by undereating all day.
- What happens to food intake when healthy college men who exercise regularly are told to sit for 10 additional hours a week for 8 weeks?
They eat less! At baseline, the subjects ate about 2,600 calories a day (47% carb, 18% protein, 32% fat). When they were told to be more sedentary, they intuitively ate less than baseline. They chose the same foods, just smaller portions. Only 1 of the 8 subjects ate more than at baseline. The moral of the study: If you get injured and cannot exercise, your body can naturally desire fewer calories. The trick is to listen to your body’s cues, not tempting food ads on TV!
- Does very slow walking (1 mile/hour) on a treadmill desk offer any health benefits?
Yes. In a study, 32 college students consumed 300 calories of glucose and then either 1) remained sedentary for two hours or 2) for two hours, alternated walking on a treadmill workstation for 30 minutes then sitting for 30 minutes. The results suggest even very slow walking helped with blood glucose control. Any exercise is better than no exercise. Being sedentary is deleterious to health.
- Men who want to lose weight should not crash diet.
They will lose not only muscle but also testosterone (a muscle-building hormone). In a three-week study, soldiers ate a high protein diet (3 x the RDA; 2.4 g pro/kg/day) but underate calories by 40% below the amount needed to maintain weight. While the very high protein intake helped counter loss of muscle, it did not maintain testosterone levels. Remember: chipping off a few hundred calories is preferable to chopping off a thousand. Two fewer cans of soda or beer a day can make a difference in weight!
- Are dieters better off eating three small meals plus three small snacks—or eating the same amount of calories but in just two meals?
For two weeks, obese middle-age women ate calorie-controlled packets of food either two or six times a day. Either way, the subjects reported being hungry. Eating six smaller meals did not appear to improve appetite response. So take your choice how often you want to eat, being sure to keep the total calories within the budget.
- Does drinking coffee for breakfast curb morning hunger pangs?
A study with 12 subjects reported no differences in appetite (and subsequent food intake) when their breakfast and mid-morning beverages were 1) water, 2) water+caffeine, 3) decaffeinated coffee or 4) decaf+caffeine. At lunch (4.5 hours after breakfast), the subjects reported similar amounts of hunger and ate similar amount of calories, regardless of their caffeine intake. The coffee did not effectively curb their appetites.
- Exercise can impact not only weight but also the kinds of microbes that grow in the gut.
In mice, the kinds of microbes differ by 40% between sedentary lean and obese mice. Even mice made obese by a high fat diet—but allowed to use an exercise wheel—had a lean phenotype compared to the sedentary obese mice with no access to the exercise wheel. The exercised mice had distinctly different gut microbes. We need more research to understand how exercise impacts gut microbes in humans and how those microbes impact metabolism and weight.
- Many lightweight rowers have to drop weight during in-season training. Does this hurt their rowing?
Likely yes! A study compared the 2K erg performance of 7 heavyweight and 7 lightweight candidates for the US Rowing National Team in December (off-season) and July (in-season). Compared to the off-season, the heavyweight rowers improved their VO2peak/fat-free mass while in-season. The lightweight rowers did not. The dieting rowers decreased total body weight by ~4.5 pounds and body fat by ~1%. They lost about 2 pounds of lean muscle. They rowed slower in the simulated 2,000-meter rowing test. The researchers recommend that lightweight rowers try to maintain their required weight throughout the year, so they can focus on performance during the season. Easier said than done…?
- Female athletes commonly have low bone mineral density. Is this related to their being light in weight?
Having low body fat? Less muscle? A study of 44 female D-1 athletes (from cross-country, tennis, basketball and soccer teams) suggests that bone mineral density significantly relates to muscle mass. The more muscle, the better the bone density. Keep lifting those weights!
- The older we get, the less we move.
Regular leisure-time exercise patterns drop from childhood to adolescence and become unacceptably low in adulthood. Is this decline related to changes in reward pathways in the brain? Researchers need more information to unravel the genetic pathways that affect exercise behavior. But before too long, we may get personalized strategies, based on our genes that will increase our lifelong desire for exercise. Stay tuned!
SIDEBAR: Nutritional and medical advice changes with new discoveries and interpretations. Always check with your medical provider and/or nutritionalist for what is best for you and your family.
And research and read information on nutrition!
Boston-area sports nutritionist Nancy Clark MS RD CSSD (Board Certified Specialist in Sports Dietetics) counsels both casual and competitive athletes at her private practice in Newton (617-795-1875). Her Sports Nutrition Guidebook and her food guides for runners, cyclists and soccer players are available at her
Nancy Clark’s Sports Nutrition Guidebook new 2013 edition and Food Guide for Soccer: Tips and Recipes from the Pros. Also available at Human Kinetics. Also see www.NutritionSportsEerciseCEUs.com for online education.
