Week of July 23, 2012
Contact: Alice Bender, (202) 328-7744

AICR HealthTalk
Karen Collins, MS, RD, CDN
American Institute for Cancer Research

Q: I’ve heard too much time watching TV is linked with weight gain, but how much is too much?

A: General recommendations for adults are the same as for children: no more than two hours of television per day. Most of us spend too much time sitting, which burns few calories and when continued for extended periods of time seems to produce metabolic changes that increase risk of heart disease, diabetes and possibly cancer. Long periods of TV time may have undesirable effects on weight and health by reducing physical activity and for several additional reasons. Over six years of follow-up in one large study of women, each additional two hours spent sitting at work was linked with a 5 percent increase in obesity and a 7 percent increase in diabetes, whereas each additional two hours of TV watching was associated with a 23 percent increase in obesity and a 14 percent increase in risk of diabetes. For many people, more time in front of the TV means more time spent eating, and this is usually “mindless” eating without paying attention to portion or even really enjoying foods’ flavor fully, making it easy to overeat. Finally, if settling down with TV leads you to stay up late and get too little sleep, that too seems to impact weight and health. For a strategy to manage weight, consider your total sedentary time, including commute time, time watching videos and playing video games, and time spent in front of computers and other screens and then find ways to incorporate more movement into your day. Several expert organizations recommend that television time for children under two years of age should be zero.

Q: Is giving up regular soda really enough to make me lose weight without going on a diet?

A: “Going on a diet” is not associated with long-term weight loss for most people, whereas working on a permanent change in one particular habit, such as reducing or eliminating sugary drinks, could be a great start for weight management. Controlled studies show that when people consume more calories from drinks, they don’t compensate for those calories by eating less of other foods, and total calorie consumption tends to be higher. Changes in drink consumption alone can produce modest weight loss. In some cases, substituting water or diet (zero-calorie) beverages for sugar-sweetened soda is even enough to achieve the 5 percent weight loss linked with significant health improvement. About 25 percent of Americans consume more than 200 calories a day in sugar-sweetened drinks. If you are in this group, you are among those most likely to notice a weight change if you give up sugar-sweetened soda. Of course, this is assuming that you don’t replace these drinks with juice or sugar-laden coffee or tea specialties or “reward” yourself for giving up soda by eating more cookies or other treats. Once your healthier drinking choices are an established habit, if you want to lose more weight, you can then look for other eating habits for which you can substitute lower calorie choices or smaller portions. On the other hand, if sugar-sweetened soda is something that you have only once a week or less, you can still focus on just one change in your eating habits to start losing weight, but you’ll see more results by changing something other than soft drinks.

Our Mission: The American Institute for Cancer Research champions the latest and most authoritative scientific research from around the world on cancer prevention and survival through diet, weight and physical activity, so that we can help people make informed lifestyle choices to reduce their cancer risk.

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