Endocrine Abstracts

Introduction: The caloric expenditure and thermogenesis are very important aspects in the obesity problem, mostly underestimated. The ‘Protein Leverage Hypothesis’ (PLH) promotes the effect of satiety, delaying the hunger sensation; thus entails the regulation of caloric intake and body weight, as well as, the modification of thermogenic activity and energy expenditure. However, the effect of high protein diet over the physiological components of energy expenditure has not been evaluated.

Objective: To evaluate in adults with obesity the effects of a caloric restriction plan with high protein content (25%) compared with low protein content (10%), over components of energy expenditure and thermogenesis, after 4 weeks of intervention.

Materials and methods: We recruited 47 adults with obesity (BMI ≥30kg / m²) aged 20-50, randomized into two diet groups. Before and after the intervention, anthropometric data were measurement. We estimated of caloric expenditure at rest by indirect calorimetry. Temperature measures in the supraclavicular cavity were recorded for 1 hour with the iButton DS1921H device. Glucose, creatinine and lipid profile were detected. Plasma levels of N¹-methylnicotinamide- (MNA-1) and N¹, N¹²-diacetylspermine were quantified by LC-MS.

Results: At baseline individuals from both groups showed no differences between them. After the intervention, significant reduction in body weight, BMI and waist circumference was observed in both groups (P<0.0001, P=0.003 and P<0.0001, respectively). In the diet group with high protein content there was a significant decrease in the levels of MNA-1 (P=0.0001), and increase in the concentrations of N¹,N¹²-diacetylspermine (P=0.03). It was also observed that the temperature of the supraclavicular cavity decreased significantly (P<0.01). When comparing the deltas of change of both groups, a lower calorie intake was observed in the group of high protein content. However, no significant changes in caloric expenditure were observed.

Conclusions: These preliminary data suggest that the diet rich in proteins induce major changes in the components of energy expenditure favoring weight loss. The changes observed in the temperature of the supraclavicular cavity support that the protein favors thermogenic activity. And the lower caloric intake in the high protein group reaffirms the idea of promoting the effect of satiety.