Drop the Carbs or Drop the Sugar? A New Study Reveals Surprising Insights

Ever wonder how different diets impact your body? A recent randomized controlled trial put two popular diets to the test—a low-sugar diet versus a low-carb plan—and examined everything from weight loss to glucose tolerance and gut health. The results? They might surprise you.

Let’s start with the basics. The study was straightforward: one group reduced their sugar intake to less than 5 percent of their total daily calories, while the other group went ultra low-carb, consuming only about 15 grams of carbs per day. That’s roughly the amount of carbs in half a large apple—definitely a strict carb cut!

Here’s the kicker: despite these very different eating strategies, both groups lost the same amount of weight, and neither diet resulted in more favorable fat loss outcomes. Why? Because regardless of whether they cut carbs or sugar, both groups consumed a similar number of total calories each day.

This study challenges the notion that calories don’t matter and that insulin levels are the primary drivers of fat storage. The low-carb group, despite lower insulin levels, did not achieve superior fat loss results. Meanwhile, the low-sugar group, consuming around 160 grams of carbs daily, lost as much weight as those on the ultra low-carb plan.

The study aimed to explore how these diets affect the number of calories burned each day. Interestingly, neither diet reduced physical activity, calorie burning, or step counts—debunking the idea that certain diets might cause you to burn fewer calories outside of your meals.

What’s particularly fascinating is that while the low-carb group initially saw an improvement in fasting glucose during the first four weeks, by the end of 12 weeks, there was no significant difference between the two groups. This finding suggests that weight loss, rather than carbohydrate intake, plays a more critical role in blood sugar management.

Perhaps most surprisingly, the low-carb group experienced worse insulin sensitivity, impaired energy metabolism, and negative changes in gut health—factors crucial to metabolic health, yet not directly tied to weight loss.

As we've discussed before, many different diets can lead to weight loss and other health benefits. However, there’s no magic in cutting out a single food group if your overall eating habits don’t change. This study demonstrates that you can eat carbs or cut them and still lose weight, as long as you maintain a calorie deficit.

Ultimately, the best diet is the one that works for you. But remember, a diverse diet—including proteins, fats, carbs, and fiber—will more likely meet your body’s needs and help you avoid the restrictive behaviors that often lead to unsustainable habits.