17 Aug Are Low Carbs Diet Dead?
Recently a new posted study gained a lot of attention from the media proclaiming that the Low-Carb Diets are not as effective as Low-Fat diets. I am grateful to the people at Examine.com who looked more closely at the study design to try to figure out what this study really means. This post will just summarize shortly what the article has to say. If you are interested you are welcome to read the article here: Really Low Fat vs. Somewhat Low Carb
- It was a six day study
- 19 volunteers resided in a metabolic unit
- Calories were reduced by 30% in both group (352g of carbs w/ 17g of fat vs 140g of carbs w/ 108g fat)
- steady protein intake
- exercised 1 hour/day on a treadmill
- both groups went through both protocols after a 2-4 week break
- Body fat analysis via indirect calorimetry
This is where it gets interesting. The “low carb group” had a decreased metabolism of about 98 kcal, while the “low fat group” had a drop of 50 kcal. This difference is not high enough to explain the variation in fat loss.
We need to understand that this study did not compare apples with apples. They used a really low fat diet and a moderately low carb diet, if they wanted to go to an extreme on the low carb diet like they had on the low fat diet and keep it equal their fat intake would have had to be in the negative, which is hardly possible.
The fat metabolism at least in the short run is dependent on glycogen as well. This could be one of the reasons for the difference in outcome compared to a steady state glycogen in the long run.
Really low carb studies have shown to lead to a slightly higher fat loss over a 6 month period but after that seem to even out with a low fat diet. In addition most low carb diets usually make up for a higher protein intake which helps fat loss.
Like the authors of Examine.com mentioned, this study was designed to see the results over a short term period. The research shows that you lose body fat on a low carb diet or a low fat diet. In the end, what matters most is the ability to adhere to it.
Nowhere was the actual food mentioned in the article. A whole foods, minimally processed, diet has many advantageous independently of the macro-nutrient intake. Fat loss is not the only factor to measure success by, like a recent study showed comparing diets heavy in meat or cheese to a high carb diet. The meat and cheese diet improved cardiovascular risk markers significantly compared to the high carb diet.
Conclusion: Don’t buy the media hype
The study was designed to fill in some of the gaps in nutrition it does not prove or disprove the effectiveness of any diet.
If you are in the process of cleaning up your diet, reducing junk food, eating more whole foods you are probably one step ahead. You can lose weight on a low fat diet or on a lower carb diet but you cannot out-train your food intake!