Ketogenic Diet: Less Prone to Lose Weight, Discover Study


TThe world of diet is consumed by ketogenic diet with low carbohydrate and high fat. But despite the immense popularity of ketone diet, some researchers and nutritionists remain concerned about their safety. It is not just the personality of the trainer and television Jillian Michaels, who has the keto: a new study suggests that people should be cautious about diet – especially women.

That's because males and females may react differently to living on a ketogenic diet, according to research presented Sunday at the annual meeting of the Endocrine Society by researchers at the University of Iowa. Their conclusion was based on research with mice: female mice were less likely than males to experience a significant loss of fat and were more likely to display sugar control on the blog in their experiments. The results of this unpublished study, the team writes, may explain the discrepancies in the success rates of this diet.

Co-author and lead investigator Jesse Cochran, research assistant at the University of Iowa, Reverse that while it is difficult to say exactly how an individual can react to the keto, this research suggests that people should consult a dietitian before starting a diet.

"It's important to think critically when reviewing this information and possibly wait a little bit for science to reach out and provide an explanation," Cochran says.

Keto diet foods
Foods allowed by Keto: meat, cheese, vegetables with low carbohydrate content.

While both men and women claim that the ketone diet works for them – many celebrities included – it has been difficult to replicate their weight loss results in the laboratory. Epidemiological studies of large samples performed by other groups showed a mixed response, and the few studies that focused solely on women found no correlation between carbohydrate cutting and weight loss. Some nutritionists have warned that there is not enough data to definitively say that dramatic change in diet is harmless. Potential risks include liver and kidney problems, nutritional deficiency and excess saturated fat.

The purpose of the keto diet is to ignite a process in the body called ketosis. A few days after you have cut the carbohydrates from your diet and deprived the body of glucose, it seeks an alternative energy source. It begins to burn stored fat and, in the process, the liver converts fat into ketone bodies. Ketones become the new fuel, and as they accumulate in the blood, the body goes into ketosis. Hypothetically, this is the time when fat burning turns into weight loss.

The results of the new study, says Cochran, may explain why previous research has produced mixed results. In the study, half of the mice did ketogenic diet and the other half adopted a regular diet as a control. The control diet was 7 percent fat, 47 percent carbohydrate and 19 percent protein in mass. Meanwhile, the ketone diet was 75% fat, 3% carbohydrate and 8% protein in mass.

This study examined the differences between male and female mice in the keto diet.

The expected weight loss of the keto diet occurred only in male rats. After 15 weeks, males had a significant reduction in fat mass, but female rats did not experience changes in weight. Speculating that estrogen might be playing a role, the team removed the ovaries from some of the female mice and tested the diets again. Those women, without estrogen, responded to the keto diet with the expected patterns of weight and fat loss.

"Our studies suggest that sex hormones can modulate the way that male versus female rats respond to ketogenic diets," Cochran says.

A very worrying effect emerged from this study: The livers of the male mice in the keto diet showed more pronounced signs of fibrosis and fat storage than the female mice also in the diet. The team found that these males had higher levels of the FG21 hormone, which previous studies have shown to be expressed and released in response to liver damage, particularly in cases of non-alcoholic fatty liver disease.

This is not the first time that liver problems have been implicated in the ketonic diet. Researchers have warned that the ketone diet can cause liver problems, because diet involves a lot of fat metabolization. But the evidence is far from conclusive: in a very small pilot study in 2007, researchers at Duke University showed that six months of the keto diet helped improve the fatty liver disease in a group of five patients.

Cochran says that based on his findings, his team would not recommend a diet for men or women until the effects and mechanisms of diet are better understood.

Clearly, more research is needed before the keto can be stated as a unique approach to good health. Cochran and his colleagues suspect that weight loss in male mice was due to compensatory mechanisms that develop in the liver as a consequence of their increased fat. Estrogen in women may have protected them from liver damage – and thus prevent them from losing weight.

"Taken together, it is possible that the weight loss we see is secondary to a hormonal response of the liver to accumulation of facts," Cochran explains. "Therefore, more work is needed before these diets can be recommended in humans for weight loss purposes."


Since the initial use of ketogenic diets (KDs) as an adjunctive treatment for epilepsy, these diets have been increasingly used to promote weight loss and reduce the risk of metabolic sequelae from severe obesity. Typical KDs are very low in carbohydrates and high in fat, promoting hepatic production of ketone bodies. Most animal studies are usually performed on male mice, and few studies have evaluated gender differences in response to DK. To explore the sex differences in response to KD, female and wild-type mice on the C57BL / 6J background were fed a control diet (CD-7% fat, 47% carb, 19% protein) or KD (75% fat, 3% carbohydrate, 8% protein) after weaning. Women on CD had higher levels of circulating β-hydroxybutyrate (β-HB) than men (2.86-fold, p <0.05). Circulating β-HB concentrations increased with KD in men and women (1.30 times and 5.05 times, p <10-4 and p <0.01, respectively) with higher concentrations in women. After 15 weeks of feeding, females in KD showed an increase in body weight (1.07 times KD vs. CD, p <0.05), while body weight decreased in males (0.88 times, p <0) , 05). Nuclear magnetic resonance imaging (MRI) revealed elevated lean mass in 18-week-old women (1.07-fold, p <0.05), but a significant reduction in fat mass in males (0.49-fold, p <0.05) <0.05) relative to sex rats in CD. Female rats in KD developed decreased glucose tolerance with an increase of 1.35 in the glucose tolerance test area under the curve (GTT AUC) (p <0.001) relative to CD females. In contrast, fasting glucose levels were lower in men in KD (131.8 ± 12.5 mg / dl vs. 169.2 ± 6.3 mg / dl, p <0.05). Despite no significant change in AUC GTT, male KD rats had elevated blood glucose concentrations 30 minutes after injection compared to male males on CD (344.9 ± 18.7 mg / dl vs. 272.0 ± 10 , 31 mg / dl, p <0.05). However, after 120 minutes, blood glucose levels returned to baseline levels. To further investigate the role of estrogen in this sexual dimorphism, female mice were ovariectomized (OVX) and randomized to receive CD or KD after weaning. At 15 weeks of age, OVX mice in KD had decreased body weight (0.84 times, p <0.0001) and fat mass (0.65 times, p <0.001) compared to mice fed CD. Despite changes in body composition, OVX mice in KD still exhibited decreased glucose tolerance with a 1.4-fold increase in AUC GTT comparable to OVX mice in CD (p <0.05). In conclusion, there are significant differences between the sexes in terms of body composition and metabolism in response to the ketogenic diet, which may be partially attributed to estrogen.


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