Restrictive low-sugar diets may harm metabolic health, study suggests

A recent study presented at Endocrine Society’s ENDO 2026 meeting highlights potential pitfalls of completely eliminating sugar from low-fat diets, with findings indicating increased insulin resistance and gut microbial imbalance in mice.

Many people trying to improve their blood sugar or overall health assume that cutting out sugar completely is the safest route. But a study presented at the Endocrine Society’s ENDO 2026 meeting in Chicago suggests that, at least in mice, a sucrose-free low-fat diet may have the opposite effect, worsening several markers linked to metabolic health.

According to the Endocrine Society’s account of the research, scientists at the Dasman Diabetes Institute in Kuwait compared two groups of mice over 16 weeks. One group was fed a low-fat diet without sucrose, while the other received a low-fat diet that included sucrose. Although the animals ended the study at similar body weights, the sugar-free group showed poorer glucose regulation, greater insulin resistance and signs of gut microbial imbalance.

The researchers also reported more intestinal inflammation and changes associated with fatty liver disease in the animals that had no sucrose in their diet. Reporting on the findings, Reuters-style health coverage noted that the results point to the gut microbiome as a possible link between overly restrictive diets and poorer metabolic outcomes. The broader scientific literature has increasingly connected microbiome disruption with inflammation and insulin resistance in type 2 diabetes.

Taiwanese nephrologist Chiang Shou-shan said the findings reinforce a familiar warning: when dietary control becomes too rigid, it may do more harm than good. The study’s authors likewise argued that the message is not to abandon moderation, but to pay more attention to overall dietary balance rather than focusing only on eliminating sugar.