Half As Heavy, but Twice As Fat: "Atkins-Style" No-Carb Diet + Exhaustive Exercise Compromise Body Composition

Image 1: Your scale is a fat liar and putting too much trust in it is a potential hazard to your health.

In the past couple of months the shrine with the image of the Dr. Atkins has begun to totter. "Lower your carbs!" What sounds easy and works pretty well as a short- to medium-term intervention for the morbidly obese 100% insulin resistant sedentary slob is getting more and more "healthy" or "newly healthy" and active individuals into serious trouble. I have been blogging about the fallacy of athletes dieting like Biggest Losers and Biggest Losers training like athletes before and do not want to go through all the arguments again. What I do yet want to do is to point you to the intriguing results of recently published (unfortunately rodent) study from the Ludwig Maximilian University here in Munich, Germany (Caton. 2012)

Extreme "Atkins diet" minimizes weight gain, but induces a "skinny fat" phenotype in exercised rodents

If you take a cursory look at the results you see exactly what the disciplines of Dr. Atkins will tell you: "It is so easy to lose weight and/or maintain your weight on this diet! You just cut your carbs and are good to go!"

Figure 1: Change in body weight in mature and adolescent rodents on "Atkins" or standard diet after the initial 10-day phase without exercise and at the end of the 21-day period with daily running exercise (to exhaustion, max. 30min; data adapted from Caton. 2012)

And in fact, though a strictly controlled rodent study certainly is not the best model for the largely psychologically determined dietary patters of human beings, the results of the study at hand clearly show that a 94% fat diet does in fact reduce the diet induced weight gain in both adolescent and mature rodents (and the practical experience of thousand of people tells us that this works for humans, as well). Compared to the rodents on the standard diet (9% fat, 33% protein, 58% CHO, 3.04 kcal/g; fat from soybean oil!), the "Atkins rats" with their calorically more than twice as dense (7.5kcal/g) lard + butter diet exhibited a lower increase in body mass - specifically in the initial 10-day phase without exercise (the sedentary slob phenomenon I hinted at in the introduction).

Figure 2: Adipose tissue weight (mature animals, left) and volume (adolescent animals, right) at the end of the study period (data adapted from Caton. 2012)

The data on the exact body composition of the animals in figure 2 does yet confirm what I (and even the advocates of Atkins diets) have been reiterating time and again: The figure on the scale is only signficant if you ware still morbidly obese (cf. "Intermittent Thoughts on How to Measure Your Success"). After all, the  "Atikins rats" may have gained only ~50% of the body weight of their peers on the standard diet, but they had significantly more subcutaneous, visceral and total body fat (volume, adolescents) and heavier epididimal and inguinal visceral fat depots (% of body weight, mature rodents) - and that despite identical caloric intakes (due to pair-feeding) and a +38% higher post-exercise energy expenditure and in the presence of 2x and 6x lower insulin levels (adolescent and mature, respectively), ~25% reduced IGF-1 levels, 2x higher leptin levels, lower cholesterol levels and identical total serum protein.

"Was that grass-fed butter and lard from pastured pigs?"

I can already hear them, the voices complaining how "unfair" this study was, how the Atkins group got "omega-6 laden fats" from "conventionally raised pigs" and butter that was not made from milk of "grass-fed cows". This, the low protein content of this extreme interpretation of the "Atkins diet" and the mere fact that we are dealing with a rodent, not a human study, are certainly all valid arguments (the latter two more than the former, though), but they don't change the basic message that no-carbing (without regular carb-loads) and working out hard don't go well together, at least not if your goal is to improve your health and physical appearance.

Image 2: If your inside looks like that of adolescent rats on the high fat diet (A), you should better forget about what the scale is telling you and how much weight you may already have lost on whatever type of diet you have been following.

Practically this means that when you have come down 100lbs from morbidly obese to chubby and are starting a preferably intense (cf. HIIT) exercise regimen to finally get in "decent shape", you better make good use of your improved insulin sensitivity and reintroduce a reasonable amount of carbs. Starting with 10g per meal, or 30g per day (not counting veggies) and building up to a level that allows you to keep losing body fat, while gaining or at least maintaining all the muscle mass you have, will also enable you to consume a decent amount of protein (get 20g of quality protein with every meal) without running into problems related to the sudden occurrence of large amounts of amino acid derived glucose in the veins of your "fat adapted" body. If, on the other hand, you are already in "at least decent" shape, fit and metabolically healthy, but still cannot lose those unaesthetic love handles. It may be time to start "playing" a little with your macros, in the way, but not just 1:1 like Adelfo has done it. A 5-6 day lower carb (carbohydrate intake placed around workouts; veggies don't count) strategy + 1weekly re-feed, where the reduction in carb intake gets you into a <20% caloric deficit will keep your insulin levels lowish and steady, will gradually reduce your glycogen stores, will ramp up AMPK and insulin sensitivity and will force your body to come up with the missing 20% of the energy from your adipose tissue, could be one way to success - a way, which unquestionably won't work for everyone and a way which will have to be tweaked to your own demands, but also a way which is not going to leave you lean on the outside and fat from within (cf. image 2).