A long-term ketogenic diet causes hyperlipidemia, liver dysfunction, and glucose intolerance from impaired insulin secretion in mice
Molly R. Gallop, Renan Fudoli Lins Vieira, Peyton D. Mower, Elijah T. Matsuzaki, Willisa Liou, Faith E. Smart, Seth Roberts, Kimberley Evason, William L. Holland, Amandine Chaix
Abstract
Ketogenic diets (KDs)-very-low-carbohydrate and very-high-fat diets-have gained popularity as therapeutic against obesity and type 2 diabetes. However, their long-term effects on metabolic health remain understudied. Here, we show that, in male and female mice, a KD protects against weight gain and induces weight loss but over time leads to the development of hyperlipidemia, hepatic steatosis, and severe glucose intolerance. Unlike mice on conventional high-fat diet, KD-fed mice remain insulin sensitive and display low-insulin levels. Hyperglycemic clamp and ex vivo glucose-stimulated insulin secretion assays revealed systemic and cell-intrinsic impairments in insulin secretion. Transcriptomic profiling of islets from KD-fed mice indicated endoplasmic reticulum (ER)/Golgi stress and disrupted ER-Golgi protein trafficking, which were confirmed by electron microscopy showing a dilated Golgi network consistent with defective insulin granule trafficking and secretion. Together, these results suggest that long-term KD leads to multiple aberrations of metabolic parameters that caution their systematic use as a health-promoting dietary intervention.