Is Low Fat or Low Carb Better for Weight Loss?

The secret to healthy weight loss may have nothing to do with how many carbs or how much fat you eat. Read on to find the surprising factor that might make all the difference.

Monica Reinagel, MS, LD/N, CNS
4-minute read
Episode #413

We live in a deeply divided nation. And don’t worry, I’m not venturing into politics. I’m talking about the never-ending debate about whether you’ll lose more weight by cutting carbs or by limiting fat.

There have been dozens of studies—and numerous meta-analyses—pitting the two approaches against one another. They’ve been evaluated not just for weight loss but other measures of health such as cholesterol, blood sugar, blood pressure, and body composition, as well. Each “side” has some put some points on the board but neither one of them is running away with the game.

Comparing Apples to Apple Jacks

Part of the problem is that the terms low-fat and low-carb are used somewhat indiscriminately. Diets described as low-carb in the medical literature might get as little as 10% of calories from carbohydrates or as much as 35% of calories. The same goes for “low fat” diets. But an even bigger problem is that categorizing diets simply by how much carbohydrate or fat they contain is like trying to categorize novels simply by how many nouns and verbs they contain.

You can follow a low carbohydrate diet and eat bacon-cheeseburgers (without the bun, of course) every night for dinner or your low carb menu could feature grilled salmon and avocado. You might be getting most of your non-carbohydrate calories from fat or you might be eating lots of protein. Who could say?

Similarly, on a low fat diet, you could start every day with sugary breakfast cereal (topped with skim milk, of course) or you could sit down to steel cut oats and fresh berries for breakfast. You might be getting very little protein or quite a bit. These uncontrolled variables could have a significant impact on things like blood chemistry and fat loss, not to mention your appetite, digestion and energy.

Same Foods, Different Proportions

That’s why I was so intrigued to read about a recent study that compared a diet that was low in carbs and high in fat with a more balanced diet—while controlling for many of these other variables. In this study, which involved 44 overweight men, the participants ate more or less the same foods but in different proportions.


About the Author

Monica Reinagel, MS, LD/N, CNS

Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes' most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation's leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.