Following a reduced-carbohydrate, high-protein diet may provide a variety of benefits to people with type 2 diabetes, including better glucose control and reduced hunger, according to a study published in the American Journal of Physiology — Endocrinology and Metabolism.
The study’s participants were 28 adults with type 2 diabetes, who were randomly assigned to follow either a reduced-carbohydrate, high-protein diet or a conventional diabetes diet for six weeks. The reduced-carbohydrate diet got 30% of its calories from carbohydrate, 30% from protein and 40% from fat, while the conventional diabetes diet got 50% from carbohydrate, 17% from protein and 33% from fat.
Researchers were interested in the effect of each diet on after-meal glucose levels, pancreatic beta (insulin-producing) cell function, gut hormone secretion and self-reported fullness. Participants wore continuous glucose monitoring (CGM) systems 24 hours a day throughout the study, and researchers gave them tests after certain meals to look at insulin secretion, beta cell sensitivity to glucose, gut hormone secretion and other measures.
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Impact of low-carb, high-protein diet on blood glucose levels
The researchers found that following a reduced-carbohydrate, high-protein diet resulted in total after-meal glucose elevation (“area under the curve”) that was 60% lower on average, as well as 24-hour glucose levels that were 13% lower, compared with the conventional diabetes diet. Participants’ after-meal insulin secretion rate was also 24% lower, while pancreatic beta cell sensitivity to insulin increased by 45% on this diet. Stomach emptying was delayed by an average of 15 minutes, while self-reported fullness between meals increased by 18%.
Certain other measurements the researchers took, such as body weight, showed small benefits from following either diet, which may indicate that either one tended to be better than what most participants followed before enrolling in the study. CGM data showed that there were five incidents of hypoglycemia (a glucose level below 70 mg/dl) in the reduced-carbohydrate group and three incidents in the conventional diet group, but none of these events were serious, caused any symptoms or required intervention to raise blood glucose levels.
These results show dramatic benefits, and no significant disadvantages or risks, linked to following a reduced-carbohydrate, high-protein diet in a small group of people with type 2 diabetes. “It is noteworthy that these results were achieved in a setting that aimed at body weight maintenance,” rather than weight loss, the researchers wrote — suggesting that the difference in diet composition, rather than a reduction in overall calories, was responsible for the benefits observed.
Based on these results, the researchers concluded, many people with type 2 diabetes may benefit from a modest shift in their diet composition away from carbohydrate and toward protein.
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