Study under review: Glucose and Lipid Homeostasis and Inflammation in Humans Following an Isocaloric Ketogenic Diet
Ketogenic diets have become very popular during the last few years, primarily as a dietary strategy for weight loss. Hence, most studies have focused on determining the effects of a ketogenic diet (KD) in this context. However, this makes keto-specific effects hard to tease out, since weight loss itself causes an improvement in several metabolic parameters and disease risk markers. This problem is further compounded because keto diets can result in spontaneous calorie restriction even if the diet isn’t explicitly meant to cut calories.
The current study was designed to address these concerns by contrasting the metabolic effects of an isocaloric keto diet with a control diet higher in carbohydrate, under energy balance, and in a highly controlled inpatient setting. Some results of this study have been published before and covered in Study Deep Dives #22, Volume 2, showing that a keto diet slightly increased energy expenditure, but didn’t lead to a higher loss of body fat compared to the control diet, as the diets were calorie-matched. This was a major ding against the carbohydrate-insulin hypothesis of obesity, which predicts that a sharp drop in carbohydrate intake should drive a drop in insulin secretion, in turn leading to increased fat loss—all other factors being equal. In the study under review, the authors followed up by shifting their focus from the effects on energy balance and storage to changes in glucose and lipid metabolism, as well as inflammatory markers.
Ketogenic diets usually result in calorie restriction in free-living scenarios, making it difficult to tell if their metabolic effects are due to the diet alone or are confounded by weight loss. The current study examined the effects of a ketogenic diet compared to a control diet higher in carbohydrate on glucose and lipid metabolism, and metabolic and inflammation markers under calorie-matched conditions.
Other Articles in Issue #56 (June 2019)
Mini: Early nutritional interventions for atopic disease prevention in infants and children
In this Mini, we summarize the main takeaways from a recent update to the American Academy of Pediatric’s report on dietary interventions that can help prevent atopic diseases.
Early vs. late time-restricted feeding: is when we break the fast important for metabolic health?
Intermittent fasting is one method that may help prevent people at risk for diabetes from developing the disease. This study explored whether the time of the eating window mattered for at-risk men.
Gluten-free menu items often not so gluten-free
Eating out can be hard for people with celiac disease or non-celiac gluten sensitivity. Gluten-free labels on menus can help somewhat, but only if they're reliable.
Can restless legs be ‘ironed out’?
People with iron deficiency have a higher risk of restless leg syndrome. This meta-analysis found that iron supplementation can have a clinically meaningful impact on symptoms.
Will red meat increase your risk of heart disease?
We've previously covered evidence suggesting that red meat isn't as heart-harmful as once thought. This meta-analysis goes a step further by comparing red meat's effects to other dietary components.
Mini: The state of the evidence for caffeine’s effect on exercise performance
There's little doubt that caffeine boosts athletic performance. The question is: does it boost certain kinds of performance better than others?
Can fasting keep the holiday pounds off?
A lot of people gain weight over the holiday season. This study explored whether intermittent fasting may be useful in putting the brakes on holiday weight gain.