Wednesday, March 7, 2012

The "Best Diet" for Obese Kids Has a Low Glycemic Load and Still 40-50% Carbs. Plus: Kids Hate Atkins / Low Carb!

Image 1: It's the "day of healthy eating", here in Germany... but wait: What exactly is "healthy eating"?
I don't know if it was a "happy coincidence", but it was a coincidence that I heard on the radio that today is the "Day of Good Nutrition" (here in Germany, at least). Unfortunately, nobody appears to really know what "good nutrition" means. While the experts are still arguing whether you may or may not eat meat, whether all carbs are created equal etc. the average customer has absolute no idea, what "good nutrition" may be. The one thing he (or she) knows is what the radio moderator mentioned as well "this means you are not allowed to go to the fast-food outlet, today". Now, while for a still astonishingly (or should I say shockingly?) large proportion of the obese population of the western convenience society, fast food remains one of the biggest obstacles to weight loss, Mc Donalds and Co. are probably not a major problem for the majority of people in the ever-growing health-conscious Internet community with its 1001 podcasts and blogs on weight loss and "healthy eating" in all its different incarnations. In the debate around paleo, ancestral, low carb, low fat, high protein, medium protein, grains-yes, grains-no, dairy-yes, dairy-no and all the other "sacred cows", the most important point in losing weight, fat and, by the way, also building muscle, i.e. consistency, is still overlooked way too often. If you consistently eat the SuperSize menu at McDonalds, you'll probably end up as obese type II diabetic. If, on the other hand, you do crossfit six times à week and follow a "healthy" low-carb diet, consistently, you end up spending bazillion of bucks for useless supplements about which you read on one of the countless bulletin boards where you posted your complains about "central fatigue" and "adrenal burnout"... as you see: Consistency is key!

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
Exercise in the form of biweekly diet-specific group sessions fo 1hr of "active 'play', resistance training, aerobic activities" were obligatory and supervised by an exercise specialist. Additionally, subjects were "encouraged" to be physically active (=at least playing Wii instead of Playstation ;-) for >30 minutes/day.

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)
The data in figure 1 does yet also show that the dietary adherence in the Atkins group was ridiculously low. While the adherence in the RGL arm of the study was constantly >75%, ...
[...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)
If we also take into consideration that the low carb group had the largest caloric deficit in the post-study period (months 6-12) and still regained the greatest amount of body fat, while the reduced glycemic load group, who consumer ~47% of their daily caloric intake in the form of carbs ate only 240kcal less than at baseline and still kept losing body fat, it is pretty clear that this is a points win for the "South Beach" = reduced glycemic load diet.

"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
As usual, these results are not representative of the average human being, not representative of the average American and by no means representative of you. So, if you asked me what a "healthy diet" looks like and expect me to answer your questions in terms of percentages and macronutrient ratios I will send you to another "guru"... if you are yet willing to accept an answer that revolves around my repeated recommendation to eat eggs, dairy (unprocessed = full fat), (organ-)meat, fish, coconut oil, olive oil, grass-fed butter, avocados, rice, potatoes, tubers, fruit (e.g. Alexa's strawberries, cf. image 2 ;-) and tons of veggies, to make sure not to starve yourself, to exercise and sleep(!), and to do all that consistently, you are no longer dieting, but just leading a healthy lifestyle - and at least for those who are still obese, this is more than enough to get to a pretty decent and moreover healthy bodyfat level - which, by the way, rarely is below the 10% mark ;-)