Low-carbohydrate diets cause obesity, low-carbohydrate diets reverse obesity: A metabolic mechanism resolving the paradox

Abstract

High-fat diets produce obesity in part because, per calorie, glucose produces greater post-prandial thermogenesis than lipids, an effect probably mediated by glucose-sensing neurons. A very low carbohydrate/high-fat/high-protein Atkins-type diet produces obesity but is marginally ketogenic in mice. In contrast, high-sucrose/low-fat diets, and very low carbohydrate/high-fat/low-protein (antiepileptic) ketogenic diets reverse diet-induced obesity independent of caloric intake. We propose that a non-ketogenic high-fat diet reduces glucose metabolism and signaling in glucose-sensing neurons, thereby reducing postprandial thermogenesis, and that a ketogenic high-fat diet does not reduce glucose signaling, thereby preventing and/or reversing obesity. Keywords obesity; low-carbohydrate diets; high-fat diets; ketogenic diets Do low carbohydrate diets promote or reverse obesity?"A systematic review of low-carbohydrate diets found that the weight loss achieved is associated with the duration of the diet and restriction of energy intake, but not with restriction of carbohydrates." (Astrup et al., 2004) "This review covers evidence from carefully controlled laboratory studies, clinical trials, studies in populations at high risk of developing obesity, and epidemiologic studies on the role of sugars, particularly sucrose, in the development of obesity. Although many environmental factors promote a positive energy balance, it is clear that the consumption of a lowcarbohydrate, high-fat diet increases the likelihood of weight gain." (Saris, 2003) These two statements from recent reviews neatly state the current consensus regarding the effect of dietary composition on obesity. In fact, despite the enormous popularity of lowcarbohydrate diets such as the Atkins diet, the South Beach diet and the Zone diet, the professional consensus is that low-carbohydrate diets (which typically implies high-fat diets) are more likely to produce obesity than reverse obesity. Although several studies have reported that low-carbohydrate diets are slightly better than low-fat diets to reduce body weight over a

Mechanisms by Which the Ketogenic Diet Reverses Obesity and Diabetes

“…However, when surgery was performed on these mice and they lost weight as is usual after surgery, mice on the high-protein diet did exhibit higher levels of blood 3-beta-hydroxybutyric acid, consistent with the ketogenic effects of the high-protein, low-carbohydrate diet during caloric restriction [20]. Under standard ad lib fed conditions, in contrast to the ketogenic diet, rather than reduce body weight, this diet promoted weight gain and other obese phenotypes just as do standard high-fat "Western" diets in mice [25]. Furthermore, despite low carbohydrate, blood glucose was not significantly reduced, and in fact trended to increase as the mice gained weight.…”

“…Nevertheless the diet reduced blood glucose, associated with an induction of FGF21 [24], consistent with the studies of Phinney et al, who demonstrated reduced blood glucose and insulin, and reduced whole-body glucose utilization, without weight loss. Our laboratory carried out a similar study using the same Bioserve diet and got essentially identical results [25], although our analysis was not as extensive as that of Kennedy et al [23]. However, we carried out an additional study.…”

Induction of ketosis in rats fed low-carbohydrate, high-fat diets depends on the relative abundance of dietary fat and protein

“…Although the mechanisms of ketogenesis might differ between humans and rats, our findings question whether people performing Atkins'-style diets being rather moderate in fat content actually reach a constant state of ketosis. Similarly, it has recently been reported that a very low-carbohydrate/high-fat/ high-protein Atkins-type diet is only marginally ketogenic in mice (34). Regardless of the occurrence of diet-induced ketosis in humans, one has to ask if the energy loss via ketone bodies in urine can quantitatively contribute significantly to the overall energy balance.…”

Nickel hydroxide electrodes as amperometric detectors for carbohydrates in flow injection analysis and liquid chromatography

“…The determination and quantification of sugars has a great significance in many fields such as food industries, medical applications, wastewater treatment, and many others [1][2][3]. The development of sensors and/or biosensors presents an advantageous alternative for ''in loco" measurements, however some aspects including durability, limits of detection and selectivity require further improvement.…”