|Image 1: It's the "day of healthy eating", here in Germany... but wait: What exactly is "healthy eating"?|
Success in life come with consistency ...
... and when we define success as "dietary success", we measure "consistency" as dietary adherence; and exactly that, i.e. the degree to which the dieters adhered to their prescribed diets was also the first and, in my mind, most important determinant of dietary success in a 2012 study involving 100 obese children aged between 7-12 years (Kirk. 2012). The scientists, who financed their study with a grant from the Thrasher Research Fund and an Institutional Clinical and Translational Science Award, took a quite intriguing look at the effects of a 3-months (+9-months follow up), three-tiered dietary intervention, with a...
- low carb arm (LC), in which the subjects had to limit their carbohydrate intake to induce ketosis (had to be measured with keto sticks daily; if the subjects were not in ketosis the diet was reviewed / carbs further restricted); that was accomplished by an initial 2-week induction phase with <20 g CHO/day and unrestricted intake of high-pro tein foods (eg, meat, poult ry,
fish, eggs) and added fats and a subsequent maintenance phase with in which the subjects were allowed to consume max. 60 g of carbs /day, with no limit on intake of high-protein foods and fats.
- reduced glycemic load arm (RGL), in which the subjects were instructed to limit
their intake of high-glycemic index (GI) foods based on a "stoplight approach" (red, high GI [>70]; yellow, medium GI
[56-69]; green, low GI [<55]); green foods were unrestricted; yellow foods were to
be consumed less frequently; red foods were restricted to <7 servi ngs/week and <2 servings/day; there were no specific restrictions on protein or fat intake .
- portion control arm (PC), in which subjects were in structed to consume "age-appropriate" amounts of grains, vegetables, fruits, lean proteins, and skim/low -fat dairy products [help me I am puking!]; calories were distributed as 55%-60% CHO, 10%-15% protein, and 30% fat; the exact dietary prescriptions aimed at a daily caloric deficit of -500kcal
Diet Wars! Atkins vs. South Beach vs. Weight Watchers
As you can see this study turns into a battle of Atkins vs. South Beach vs. Weight Watchers and the most important result, i.e. the reduction in body fat percentag (cf. figure 1), shows once more that "done right", or I should say "done the way it is supposed to" and "done consistently", everything works!
|Figure 1: Change in body fat (%) over the 3 months controlled intervention and the follow up period - left; adherence to diet (%) - top-right; glycemic load (g/1000kcal) - bottom-right (data calculated based on Kirk. 2012)|
[...i]n the LC group, only 16% of subjects tested positive for urinary ketones at any point (only 8% [6 of 76] of all tests done), and CHO intake exceeded the goal of 60 g/day at all time points (3 months, 85.3 +/- 11.8 g; 6 months, 108.2 +/- 11.6 g; 12 months, 122.6 +/- 11.4 g).Against that background it is actually quite astonishing that the subjects lost that much body fat. It does yet not explain, why the body fat levels (measured by DEXA, not with hilarious body impedance scales) of the "Atkins dieters" bounced back up so profoundly (within the statistical margin, back to where they came from) in the months following the controlled intervention, while the fat loss in the other groups did slow down, yet remained persistent (and that despite the fact that the glycemic load was still -26% lower than in the RGL group).
|Figure 2: Daily caloric deficit in months 1-3 (I), months 4-6 (II) and months 7-12 (post) - left; ration of body fat lost / reduction in caloric intake - right (data calculated based on Kirk. 2012)|
"Do you want to tell me that South Beach was the way to go?"
|Image 2: This is Alexa Iwan who "advertises" her strawberries on the website for the Day of Healthy Eating|