Low Carb trumps Low Fat?
If you're a savvy nutrition enthusiast, you probably know that a variety of diets can improve health and lead to weight loss. But in the media, low-carb and low-fat diets have waged an epic battle over the past few decades. The latest comes from a year-long study of obese patients, which claims to shed new light on the topic.
Does this study tell us anything helpful, or does it just confirm what we already know? Headlines in the past 24 hours have largely touted the study as eye-opening, even tying it into the newly low-carb (and much thinner) Lebron James.
While most journalists are chasing the sensationalist story: “low carb proven to be superior, ” few actually delved into the study to see what researchers found. When you read the full study, key nuggets jump out that most people have missed. Let's dive right in and break down the details. If you're short on time, read the blue boxes now and then come back and read the details later.
We'll analyze this paper using the PICO method, which researchers often use to frame randomized trials. It stands for:
[P]opulation - The study focused on obese people in Louisiana. Unlike most previous trials, this one included a sizable non-white population. Black people made up a little over half of the group.
ntervention - Participants were split into two groups: the low carb group were told to eat less than 40 grams of carbs per day while the low fat group was to take in less than 30% of their calories from fat. The low fat group also aimed to keep saturated fat under 7% and carbs around 55%, which is in line with the current U.S. dietary guidelines.
omparator - This just refers to the control group. The researchers wanted to know the effects of a low-carb diet (the intervention) and compared it against a low-fat diet (the comparator). The comparator is often the current standard of care. In this case, the low-fat diet was very close to what physicians typically prescribe for people at risk for heart disease.
utcome - The outcomes researchers were most interested in were weight loss and cardiovascular risk factors like LDL, HDL, and waist circumference. They also measured a few other factors, like markers for diabetes.
Things to Note
This study was a bit different than previous low-carb trials. None of the participants had diabetes, heart disease, or kidney disease. Having healthier participants means that the researchers could apply the results to a broader group, not just people who were already sick. One thing that wasn't emphasized in the paper or media: almost 90% of the participants were female! If you're using this study to guide dietary recommendations for obese males, just note that only 9 out of 75 people in the low-carb group were men.