What completely cutting out sugar could do to your health

Completely removing sugar from the diet may seem like a straightforward route to better health, but a preliminary study suggests that an extreme approach could damage metabolism instead.

The experiment involved rodents, with only six mice in each group. The researchers found that mice on a strict sugar-free diet did not gain weight and appeared healthy by standard measures. Yet their metabolic health deteriorated.

Hormonal signals pointed to problems in the digestive system, while the animals lost the ability to remove glucose from the blood efficiently. The findings suggest that body size alone may not reveal whether metabolism is functioning properly.

The proposed explanation centers on the gut microbiome. Some beneficial bacteria need simple sugars and carbohydrates to produce compounds that help maintain the intestinal lining, support nutrient absorption and encourage hormones linked to appetite and insulin response. Removing those sources of fuel weakened the gut barrier and reduced helpful microbes involved in immune function.

The study’s diet was also extremely low in fat, unlike the typical Western diet described as high in both fat and sugar. The results therefore raise questions about radical eating regimes, but their relevance to people remains uncertain because the experiment used a very small number of mice and a digestive system that differs substantially from humans.