Fit or Fiction, Posted on Feb 22nd 2011 1:00PM by Liz Neporent
Filed Under: Diet & Weight Loss,
The average 12-ounce can of cola delivers 150 almost all of them from sugar. So it would seem the more virtuous choice would be to crack open a can of diet soda every time you have the urge for a little fizz. Anyone watching his weight feels virtuous making this choice, because who doesn’t believe it protects one’s waistline — and overall health — from an assault of unnecessary, empty calories?
Maybe it’s time to think again. No study to date has ever shown diet soda to be especially useful in helping people prevent or shed unwanted pounds. In fact, there is a growing body of research that seems to suggest that high diet soda consumption is associated with a higher risk of obesity and may surprisingly carry an even greater risk of obesity than drinking regular, full-calorie and -sugar drinks.
In 2005, University of Texas Health Science Center researchers in San Antonio reported their findings culled from seven to eight years of data on 1,550 Mexican-American and non-Hispanic white American women aged 25 to 64. Of the 622 study participants who were of normal weight at the beginning of the study, about a third became overweight or obese during the course of the investigation. For those who drank half a can of regular soda on a daily basis, their risk of being obese was 26 percent; for those who drank the same amount of diet soda, their risk jumped to 36.5 percent. Women who drank one to two cans a day fared even worse: Their obesity risk rose to 47 and 57 percent, respectively. In fact, for each additional can of diet soft drink a woman guzzled per day, her risk of being overweight went up by 65 percent and risk of obesity shot up 41 percent.
Although this sounds like pretty damming evidence, few experts are jumping to the conclusion that there is a direct cause and effect between diet soda and weight gain. The study is flawed in that it didn’t track eating habits and total calorie intake or caloric expenditure, even though the two subject groups were notorious for their poor diet, exercise and other lifestyle habits, at least as demonstrated in other studies. Still, other investigations have come up with conclusions along the same lines.
One explanation could be that artificial sweeteners alter metabolism and brain chemistry in some way. They may tell the brain that the body has eaten something high in calories, but since it really didn’t, the brain directs the body to go in search of those calories elsewhere, like from a sizable slice of pie or a yummy candy bar. Another explanation put forth by the University of Texas researchers is that perhaps people who’ve already begun to gain weight in the first place switch over to diet soda to prevent further weight gain but don’t make the other corrections necessary to either lose weight or stop continued weight gain.
It’s also possible that people mistakenly equate drinking diet soda to actually being on a diet. If you rationalize a liquid calorie savings as a license to gorge, there’s little chance you’ll keep your weight under control for very long. I once had a client who drank a 64-ounce bottle of Diet Coke and ate a one-pound bag of M&Ms almost every night. She used to tell me it wasn’t so bad because the soda contained no calories. Then I explained to her that she was eating more than 2,300 calories. In one sitting. Every night.
Whether diet soda causes weight gain, is linked to weight gain in some way or is simply a marker habit for obesity (meaning that the fact that someone drinks the stuff is something to watch out for) is impossible to say just yet. Only time and better studies will tell.
If you’re serious about getting your weight under control and nothing seems to be working, it’s definitely worth trying to at least cut back on artificial sweeteners and see if it helps your efforts. (There are certainly many other reasons you might want to curtail this habit anyway, like cuting back on caffeine, saving money and giving your teeth a break.) If you don’t want to give it up, keep a food journal and track your total caloric intake to make sure you’re not using diet items as a justification for other poor nutritional choices.
I admit to being a former diet cola fiend myself. I cut way back a few years ago and now have only an occasional can. My weight hasn’t changed, but I’m certainly less bloated and I sleep better because of the caffeine reduction and the fact I don’t have to get up six times a night to pee.
What about you? Have you ever ordered a diet soda with a ginormous piece of cake? Or do you think diet soda is a vile, evil nectar? Sound off in the comments section or chirp off to me on Twitter.
Liz Neporent holds a masters degree in exercise physiology and is certified by the American Council on Exercise, the American College of Sports Medicine and the National Strength and Conditioning Association. She has coauthored various books on health and fitness. Follow Liz on Twitter, @lizzyfit.