It seems like every week, there is some new diet out there. Low carb, high carb, no carb- it's enough to confuse even those of us who have a pretty good grasp of dieting, metabolism and fitness. Who to believe and which is right for you? Read on, and the results may surprise you.
Firstly, we need to understand the concept of "energy deficit", calories, and how it's related to weight loss. A pound of body fat is equal to roughly 3500 Calories. If, for instance, you burn an extra 500 cal more than you take in, then in one week you will have expended 3500 Calories more than you ate or had an energy deficit of 3500 Cal. Got that? In other words, you burned a pound of stored fat over that week. The same is true on the other side. Take in 500 Cal more than you burn each day and after one week, you'll have an energy surplus of 3500 Cal or an extra pound of body fat.
All diets try to play upon this energy deficit theory by trying to get the dieter to burn more calories than taken in. That can be done by either taking in fewer calories, burning more calories, or usually, some combination of both. In this blog, I will deal with 5 popular diets, namely, Weight Watchers (www.weightwatchers.com), LEARN (Lifestyle, Exercise, Attitude, Relationships, Nutrition, www.thelifestylecompany.com), Ornish (www.ornish.com), Zone (www.zonediet.com), and Atkins (www.atkins.com). Most of these diets attempt to reduce calories taken in while trying to increase some physical activity though they differ in the make up of the carbohydrate/protein/fat profile recommended. Weight Watchers and LEARN allow a combination of the three food categories with more attention paid to calories (or points in Weight Watchers) as well as attitude changes, physical activity and lifestyle modification in the LEARN diet. Less emphasis is placed on where the calories come from. Ornish puts emphasis on vegetarian based eating with rather strict limits of fat intake (i.e. less than 10% of total calories). Both Zone and Atkins stress cutting down on carbohydrates to various degrees. Zone suggests a carb/protein/fat breakdown of 40/30/30 respectively, while Atkins is stricter with regard to carbohydrate intake but puts minimal restriction on fat intake. For details on any of these diets, I suggest visiting the aforementioned websites.
Which is best? [Drum roll please]. That all depends. Unfortunately, it's not that straight forward. Two scientific trials of conventional diets (i.e. Weight Watchers, LEARN) vs. low-carbohydrate diets (i.e. Atkins, Zone) showed that in the first 6 months the low-carbohydrate dieters lost more weight than the conventional dieters. However, by 12 months, there was no significant difference and the drop-out rates and adherence were poor in both groups. In another trial, which lasted for a year, dieters were placed in either Weight Watchers, Zone, Atkins or Ornish diets. The drop out rates were disturbing, ranging from 35%-50% in all groups. For those who completed the diets, weight loss ranged from 2.1-3.3 kg. More importantly, there did not seem to be a significant difference between the groups.
Conclusion? It appears that low-carb diets may be somewhat more effective in the short-term with weight loss at 6 months being larger. However, at 12 months, there is no difference and adherence is poor. Simply put, after checking with your primary care provider and figuring which is right for you, it doesn't really matter if you're in it for the long term (1 year or more). After all, the long-term is what counts if you're trying to lead a healthier, fitter life. For those of you who like to see quick results, however, there may be some slight advantage in low- carb diets at the outset.
Published On: July 03, 2008