Diet? Exercise? Or both?

Posted by Liz on Apr 25, 2011 in diet, exercise, weight | 3 comments

A novel study from the Fred Hutchinson Cancer Research Center shows that combining dietary changes with exercise yields the best the results. While this isn’t necessarily surprising, it is important, especially as the metabolism starts to slow as we grow older.

So what’s the 4-11 on this study?

Previous studies have shown that moving your body is important, not only for maintaining weight but also for preventing conditions like osteoporosis, which is a huge problem for both men and women as they age.  Other studies suggest that watching what you eat, both in terms of calories and content, are key. You can check out those posts here.  But how do the two strategies differ when it comes to weight loss?

To find the answer, researchers separated 439 overweight or obese (by body mass index > 25) postmenopausal women (average age 58 years) into four groups:

1. > 45 minutes of moderate to vigorous exercise, 5 days a week (225 min/week), including walking/hiking, aerobics and biking with the goal to reach 75% to 80% of target heart rate and 45 min/daily exercise
2. A weight loss strategy based on a daily intake of 1,200 to 2,000 calories comprising <30% from fat coupled with individual and group dietary counseling, diet journaling and weekly weigh-ins, with the goal to achieve a 10% weight loss
3. A combination of exercise and weight loss per above
4. No intervention

Over the course of the 1-year study, women in the diet group lost 8.5% of their total body weight (a mean 15.8 lbs) while those in the exercise only group lost 2.4% of their overall weight (mean 4.4 pounds). However, women who participated in both diet and exercise strategies lost 10.8% of their overall weight (mean 19.6 lbs). Moreover, although all women who had some active intervention lost inches off their waistlines, the greatest decline — almost 3 inches –was in women who watched their diet and exercised regularly. The same pattern was observed for the overall percentage of body fat that the women lost over the course of the study: 4.2% for diet alone, 1.6% for exercise alone and 5.9% for a combined strategy.

Importantly? The researchers say that when women added the 5 days weekly of exercise to a diet program, however tedious and time consuming, the majority were able to attain the 10% weight loss goal.  They add that both the American College of Sports Medicine and the US Department of Health and Human Services Physical Activity Guidelines Committee suggest that current activity level recommendations (which are roughly 30 minutes daily) be upped to as much as 60 minutes per day.

Granted, this is a hard pill to swallow. It’s difficult to find time in daily schedules to exercise as much as an hour a day AND eat properly. And lord knows, it’s not easy. Can you do one or the other? You can, but the best strategy is both.

A few tips to get you started:

• Start slowly and build up over time.
• Don’t beat yourself up if you miss a day or cheat on your diet goals. While moderation is key and diligence is important, so is the occasional cheating! Deprivation is not a rule, ever!
• The same goes for missing a day of exercise. And remember, a little is better than none at all.

So the skinny (pun unintended) is that the greatest potential lies in doing the greatest amount possible. The only thing at risk is your health. And that’s a pretty big deal.