When is a Calorie not Just a Calorie?
August 28, 2012
You’ve been hearing it forever. Especially if you’ve been watching your waistline, have ever counted calories, or ever tried to diet. Weight balance is about calories in versus calories out.
This simple principle is based on the fact that each of the macronutrients we consume, such as fat, protein and carbohydrate, contain a certain amount of calories per gram. Protein and carbohydrate have 4 calories/gram and fat has 9 calories/gram. No matter what combination of foods we eat, by adding up all the caloric values of those foods, we will have a single number, and that number tells us whether or not we will gain or maintain our weight. Eat 2000 calories daily? Then burn 2000 calories daily. Whether you eat 2000 calories worth of brownies (brownie diet, anyone?), or brown rice or black beans, those 2000 calories will affect your body the same way.
However, a new study suggests that this logic may be wrong. A study by Children’s Hospital Boston and Brigham and Women’s Hospital Boston, was conducted on 3 groups of young adults, each following a diet with equal amounts of calories, but different amounts and types of carbohydrate, fat, and protein. The researchers wanted to study not weight loss, but weight maintenance – which is, of course, the bane of every dieter’s existence.
When you lose weight, you also decrease the amount of calories you expend each day making your efforts to maintain your weight even more difficult. The researchers put the study participants on 3 different diets, trying to determine which of them decreased a person’s metabolism the least after weight loss. The first diet was a standard low-fat diet, one that the medical establishment has been proclaiming for years is the best for overall health and weight loss. Fat is 20% of calories, and carbohydrate is 60%. However, these carbs could be of any quality – such as highly processed white flour. The second diet was Atkins-style with 10% of calories from carbohydrate. The third was a low-glycemic diet, with 40% calories from carbohydrate, all from sources that do not spike blood sugar, such as cooked rolled oats, beans, and other whole grains.
The diet that increased caloric burn the greatest (which is a great help in maintaining weight) AND kept the participants the healthiest was the low-glycemic diet. The Atkins-style diet actually beat the low-glycemic diet in calorie burn, but the people who followed this diet experienced an increase in their C-reactive protein levels or ‘CRP’ which is a marker of inflammation (not a good thing). High levels of the marker have been associated with increased risk for heart disease and other chronic diseases. The diet that decreased caloric burn the most was the low-fat diet, with 20% calories from fat.
It seems that the quality of your calories really do matter, and the low-glycemic diet is one based on balance. Focusing on whole foods, with carbohydrates that are in their whole, unprocessed form is always a good thing. Low-glycemic carbohydrates don’t spike blood sugar, which doesn’t trigger your body to store extra fat. You can read more about this effect here. Reducing the amount of sugar, white flour, and other processed carbohydrates from the diet will not only keep you healthy, but your waistline in check too.
So the next time you see an ad for yet another ‘Amazing Cookie Diet’ you might want to put down the magazine and grab an apple or a Zing bar instead.
What do you think about this study? What have you experienced when trying to maintain weight loss?
Christine Weiss MS, RD is a dietitian and Bastyr University graduate who counsels people dealing with food allergies, diabetes and digestive issues. She loves working with Zing Bars to raise awareness about healthy living through online media. She can be found at Eating It Up online.