A very low carbohydrate ketogenic diet improves glucose tolerance in ob/ob mice independently of weight loss.
In mice of normal weight and with diet-induced obesity, a high-fat, low-carbohydrate ketogenic diet (KD) causes weight loss, reduced circulating glucose and lipids, and dramatic changes in hepatic gene expression. Many of the effects of KD are mediated by fibroblast growth factor 21 (FGF21). We tested the effects of KD feeding on ob/ob mice to determine if metabolic effects would occur in obesity secondarily to leptin deficiency. We evaluated the effect of prolonged KD feeding on weight, energy homeostasis, circulating metabolites, glucose homeostasis, and gene expression. Subsequently, we evaluated the effects of leptin and fasting on FGF21 expression in ob/ob mice. KD feeding of ob/ob mice normalized fasting glycemia and substantially reduced insulin and lipid levels in the absence of weight loss. KD feeding was associated with significant increases in lipid oxidative genes and reduced expression of lipid synthetic genes, including stearoyl-coenzyme A desaturase 1, but no change in expression of inflammatory markers. In chow-fed ob/ob mice, FGF21 mRNA was elevated 10-fold compared with wild-type animals, and no increase from this elevated baseline was seen with KD feeding. Administration of leptin to chow-fed ob/ob mice led to a 24-fold induction of FGF21. Fasting also induced hepatic FGF21 in ob/ob mice. Thus, KD feeding improved ob/ob mouse glucose homeostasis without weight loss or altered caloric intake. These data demonstrate that manipulation of dietary macronutrient composition can lead to marked improvements in metabolic profile of leptin-deficient obese mice in the absence of weight loss.
Badman
Michael K
MK
Division of Endocrinology, Beth Israel Deaconess Medical Center, Center for Life Sciences, 7th Fl., 330 Brookline Ave., Boston, MA 02215, USA.
Kennedy
Adam R
AR
Adams
Andrew C
AC
Pissios
Pavlos
P
Maratos-Flier
Eleftheria
E
D000818:Animals; D002153:Calorimetry, Indirect; D050528:Diet, Carbohydrate-Restricted; D055423:Diet, Ketogenic; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000235:genetics; D018149:Glucose Intolerance / Q000178:diet therapy*; D005951:Glucose Tolerance Test; D006706:Homeostasis / Q000502:physiology; D018836:Inflammation Mediators / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D015850:Interleukin-6 / Q000378:metabolism; D020738:Leptin / Q000097:blood / Q000494:pharmacology; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D009765:Obesity / Q000178:diet therapy; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction; D014280:Triglycerides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015431:Weight Loss / Q000502:physiology*
D018836:Inflammation Mediators; D015850:Interleukin-6; D020738:Leptin; D014280:Triglycerides; D014409:Tumor Necrosis Factor-alpha; C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors; D012313:RNA