Time-restricted eating and high-intensity exercise may synergistically enhance health: Study

Researchers from the University of Sfax in Tunisia discovered that combining time-restricted eating with high-intensity functional training may improve body composition and cardiometabolic parameters more than either practice alone.

The study published in the journal PLOS ONE explained that time-restricted eating limits when individuals eat but not what individuals eat. High-intensity functional training combines intense aerobic and resistance exercise.

Time-restricted eating involves limiting food intake to specific windows of time, promoting metabolic flexibility and weight management. High-intensity exercise, characterized by short bursts of intense activity, enhances cardiovascular fitness, muscle strength, and metabolic rate. When integrated, these approaches may optimize insulin sensitivity, blood sugar control, and lipid metabolism. Additionally, the combination may promote fat loss, muscle growth, and cellular repair mechanisms.

In the study, researchers assigned 64 women with obesity to one of three groups: time-restricted eating (diet only), high-intensity functional training (exercise only), or time-restricted eating plus high-intensity functional training (diet and exercise). The participants following only the time-restricted eating regimen ate only between 8 a.m. and 4 p.m. Subjects in the functional training groups worked out three days a week with an instructor.

The results showed that all three groups experienced significant weight loss and decreases in waist and hip circumference after 12 weeks. All three groups also showed positive changes in glucose and lipid levels.

Researchers also observed improvements in fat-free mass and blood pressure among those in the diet and exercise group as well as the exercise groups. However, those improvements weren’t seen in the diet-only group.Subjects in the diet and exercise group generally saw more pronounced changes in body composition and cardiometabolic parameters than either diet or exercise alone groups.

“Periods of fasting force the body to burn calorie reserves – fat, after immediate reserves are consumed – and intense physical activity also burns fat. Time of eating can affect a person’s weight. Consuming a larger number of calories later in the day can leave less time for a body to metabolize calories, as there is less calorie consumption when you sleep. Although more research is needed, it’s believed that eating in alignment with circadian rhythms might enhance metabolism, although the ideal timing for meals can vary based on individual lifestyle and metabolic differences,” said the study authors.

Reference:Ranya Ameur ,Rami Maaloul ,SémahTagougui,FadouaNeffati,Faten Hadj Kacem,Mohamed Fadhel Najjar,AchrafAmmar,Omar Hammouda; Unlocking the power of synergy: High-intensity functional training and early time-restricted eating for transformative changes in body composition and cardiometabolic health in inactive women with obesity; PLOS ONE.