In a recent study published within the journal Clinical Nutrition ESPEN, researchers compared the results of fasting, ketone salt supplementation, and a one-day isocaloric ketogenic weight loss plan on the appetite perception and energy expenditure of healthy adults.

Randomized Controlled Trial: Impact of one-day fasting, ketogenic weight loss plan or exogenous ketones on control of energy balance in healthy participants. Image Credit: Epine / Shutterstock

Background 

The ketogenic weight loss plan comprising high fat and low carbohydrate content has grow to be a successful and popular strategy for weight reduction, with the appetite-suppressing effects of acetoacetate (AcAc) and beta-hydroxybutyrate (BHB) ketone bodies and the next expenditure of energy being possible explanations for its success. Moreover, the low carbohydrate content of ketogenic diets also leads to a decrease in insulin levels and glycemia, and patients with type 2 diabetes and obesity have reported spontaneous weight reduction inside two weeks of following a ketogenic weight loss plan.

Nonetheless, the high-fat content of ketogenic diets poses some problems, corresponding to a rise within the low-density lipoprotein cholesterol as a result of the high-fat content, and leads to other health issues, corresponding to gastrointestinal discomfort. Compared, short-term weight loss plan options corresponding to intermittent fasting and a 24-hour ketogenic weight loss plan are more favorable. Moreover, lately, exogenous ketones in the shape of racemic ketone salts have been used to realize ketosis.

In regards to the study

In the current study, the researchers recruited eight adults between the ages of 25 and 30 years who had a body-mass index (BMI) between 19 and 29 kilograms per square meter and had habitual physical activity levels starting from low to normal. The study group comprised 4 males and 4 females who were included only after they were constantly using hormonal contraceptives, as that may circumvent the influences of the menstrual cycle on energy expenditure.

Individuals who practiced alternative food habits corresponding to veganism or vegetarianism, had chronic diseases, had food allergies, were on regular medications, smoked, had claustrophobia, were pregnant or lactating, had a high level of physical activity, had lost greater than 5 kg within the last three months, or were currently on weight reduction diets were excluded from the study.

Height and body weight were measured at baseline, and air displacement plethysmography was used to evaluate fat mass, which was used to calculate the fat mass index. Indirect calorimetry was used to calculate the resting energy expenditure. 4 interventions consisting of an isocaloric formula weight loss plan, total fasting, isocaloric ketogenic weight loss plan, and exogenous ketone salt supplements were conducted for twenty-four hours, with differing chronological orders of every intervention for the primary and last 4 participants.

A bicycle ergometer was used to measure work and energy during three rounds of 20 minutes of exercise to keep up a physical activity level (PAL) of 1.65 during interventions. A controlled weight loss plan with a set composition of macronutrients was provided to all participants before starting the interventions to determine equal baseline conditions. A complete-room indirect calorimeter was used to conduct the interventions and measure the energy requirements of every individual.

Blood and urine samples were taken postprandially at different time points to evaluate the degrees of BHB, AcAc, insulin, free fatty acids, C-peptide, and dopamine. Appetite rankings were also evaluated at various time points after a meal.

Results

The outcomes reported that the full fasting and ketogenic diets resulted in significantly higher levels of ketone as in comparison with the isocaloric formula weight loss plan, and the exogenous ketone complement weight loss plan resulted in barely higher levels of ketones than the opposite three interventions. While the sleeping and total energy expenditure didn’t vary between the isocaloric formula, total fasting, or exogenous ketone supplementation diets, the ketogenic weight loss plan increased each energy expenditures.

The carbohydrate oxidation was barely lower within the exogenous ketone supplementation weight loss plan as in comparison with the isocaloric formula weight loss plan, which resulted in a positive carbohydrate balance. Moreover, the absence of increased energy expenditure with the exogenous ketone supplementation indicated that the metabolic switch from glucose to ketone utilization can’t be achieved when ketones and glucose are each available to the body.

The researchers imagine that the increased energy expenditure with the ketogenic weight loss plan may very well be explained by the upregulation of energy-demanding pathways of the triglyceride fatty acid cycle and hepatic gluconeogenesis. Furthermore, comparisons of cumulative energy expenditure between the full fasting and ketogenic diets indicated that the energy-demanding pathways increase only after about 16 hours of the ketogenic weight loss plan.

Conclusions

Overall, the outcomes indicated that an intermittent 24-hour ketogenic weight loss plan could increase energy expenditure and help maintain energy balance. Nonetheless, the addition of exogenous ketone salts as supplements to an isocaloric weight loss plan doesn’t contribute to regulating the energy balance.