A very low-calorie keto diet reduces fat and oxidative stress and improves metabolic health in obesity

A study published in the journal Biology and medicine of free radicals shows the effects of a multiphasic, very low-calorie ketogenic diet on serum markers of oxidative stress in individuals with obesity.

Study: A multiphasic ketogenic diet with very low calorie intake improves serum redox balance by reducing oxidative status in obese patientsPhoto credit: Alkema Natalia/ Shutterstock

background

Obesity has become a major public health problem due to its serious health consequences. Obesity, characterized by excessive fat accumulation, is associated with a reduction in life expectancy of 5–20 years and an increased risk of several non-communicable diseases, including cardiovascular and metabolic diseases and certain cancers.

There is evidence that obesity-related complications can be reduced by losing 5-10% of your weight. Various lifestyle interventions, such as healthy eating habits and regular physical activity, have shown promising results in weight control.

Low-calorie diets high in nutraceuticals and phytochemicals have been found to reduce complications associated with obesity and increase life expectancy through their anti-inflammatory and antioxidant effects.

In this study, scientists investigated the effectiveness of a multi-phase, very low-calorie ketogenic diet in maintaining the body's redox status and influencing anthropometric and biochemical parameters.

Study design

The study was conducted on 40 adults suffering from obesity. They were prescribed a multi-phase, very low-calorie ketogenic diet for eleven weeks. The daily intake of fiber, vitamins and minerals was in accordance with international recommendations.

Anthropometric parameters, body composition parameters, calorimetric measurements, and standard laboratory markers of glucose and lipid metabolism were evaluated at the beginning and end of the nutritional intervention. Serum antioxidant status and levels of oxidative stress markers were also evaluated at both time points.

Important observations

Analysis of baseline characteristics revealed that dyslipidemia was the most common comorbidity among participants. All were physically active, but their activity level was low.

After the 11-week multi-phase, very low-calorie ketogenic diet intervention, significant improvements in body weight, body mass index (BMI), waist circumference, and waist-to-hip ratio were observed.

At the end of the intervention, a lower obesity class was observed in the entire study population. A significant reduction in abdominal obesity was observed in 18% of participants.

After the 11-week intervention, a significant reduction in fat mass, fat-free mass, body water and cell mass was observed.

Regarding metabolic effects, the intervention was shown to improve glucose and lipid metabolism without causing changes in serum total protein and albumin levels.

Analysis of oxidative stress markers and antioxidant status in serum and erythrocytes revealed that the 11-week intervention is able to improve serum redox balance by reducing oxidative stress markers, including total oxidative status, lipofuscin, lipid hydroperoxides, and malondialdehyde (MDA).

Changes in anthropometric measures, body composition, and parameters of glucose metabolism were significantly associated with changes in serum markers of oxidative damage.

Further statistical analyses revealed that the change in serum lipofuscin level significantly predicted the changes in body mass index, fat mass, visceral adiposity, and insulin sensitivity. Similarly, the variations in serum MDA level and total oxidative status were identified as significant predictors of BMI and fat mass changes, respectively.

Significance of the study

The study concludes that following a multi-phase, very low-calorie ketogenic diet for 11 weeks has beneficial health effects, as evidenced by reductions in body weight and fat mass, and improved glucose and lipid metabolism. These beneficial health effects are associated with reduced serum oxidative stress markers and improved serum redox balance.

An average weight loss of about 18 kilograms was observed among participants. This can be attributed to reduced energy intake, protein-induced satiety, and hormone-driven appetite control.

The average reduction in free fat mass, muscle mass, and total body water among participants after the 11-week nutritional intervention was 2.7 kilograms, 1.8 kilograms, and 2.0 kilograms, respectively.

A reduction in total body water could be due to increased water excretion (required for the removal of ketone bodies), decreased sodium intake, and glycogen depletion in the liver and muscles.

These observations suggest that the multi-phase, very low-calorie ketogenic diet is capable of reducing fat mass while maintaining muscle mass in overweight individuals.

A reduction in respiratory quotient without changes in resting metabolic rate suggests a shift toward preferential lipid oxidation over carbohydrate for energy, thereby optimizing oxygen metabolism. This metabolic adaptation is an indicator of long-term weight maintenance and improved metabolic health.

Overall, the study highlights the interactions between obesity, glucose metabolism and redox homeostasis in the development of obesity. The study also identifies serum lipofuscin as a reliable redox marker in obesity.