Low-Fat vs. Low-Carb Diets: The Answer You Probably Never Expected
Last Update: 10 August 2021
An impressive new study published in the National Institutes of Health (NIH) shows that the fad low-carb diets that have become popular may actually be useless. In most nutrition studies, participants self-report what they have had to eat. As the experiment goes on, this becomes less and less accurate due to the simple fact of human error.
Instead, however, scientists broke it down on the macronutrient level to determine if carbohydrates deserve all of the recent hatred. Their aim was to challenge certain advocates who claim carbs affect insulin in various ways that make them less-than-optimal for losing weight or maintaining a lean weight.
With that said, it is important to point out that many times low-carb restrictions simply cut out the “right” foods, as many junk food items are packed with them. Again, we see that it isn’t truly the carbs that matter but the overall restriction of calories.
Up until now, there hasn’t been an intense, highly-monitored and controlled analysis of the actual macronutrients themselves and how they function. To tackle this, the lead scientist Kevin Hall narrowed down on a way to directly measure the effects of both carbs and fats on energy expenditure, bodyweight, and BMI.
The 19 volunteers (9 females and 10 males) were required to stay inside of a metabolic unit for 6 days where they were divided into two groups:
- The low-fat group
- The low-carb group
Both groups had an overall calorie restriction of 30% from the baseline established at the beginning of the trial. The low-fat group was allowed to eat a maximum of 17 grams of fat. The low-carb group was allowed to eat a maximum of 140 grams of carbs.
To make the study even more air-tight, the team of researchers had all of the participants come back two weeks after the initial test to switch groups.
To collect extremely precise results, the metabolic chamber measured the amount of heat being released by each individual based on the specific amount of oxygen and carbon dioxide being released over a given time period.
As might be expected, the low-carb diet did result in lower insulin levels. Yet, this did not lead to more fat loss over time, essentially debunking the carb-insulin theory.
A low-carb diet does not have an advantage over a low-fat diet based simply on the macronutrient. Falling into the hype of a diet simply because of its fat or carb content is a terrible idea.
With that said, this is not an attack on low-carb diets. As mentioned above, in many cases they lead to higher protein and limited junk food—both of which are great.
Bottom line: losing weight does not rely on manipulating carbohydrates or fats, but instead on simply eating less.
The science has spoken. There you have it.