Background: Previous studies have showed differences in the amino acid (AA) composition in the plasma of people with obesity when compared to lean individuals, but the perturbations of AA concentrations in obesity and the dynamics of AA changes after weight loss is not fully understood.
Objectives: The objective of the study was to evaluate the effect of a short-term weight reduction program on the metabolic status and plasma AA levels in individuals with obesity.
Material and methods: A total of 24 adult Polish patients with a BMI between 34 and 49 kg/m2 were enrolled in a 3-week controlled body mass reduction program based on everyday physical activity and a hypocaloric diet (25-30% less than total daily energy requirements). At baseline and after the program, anthropometric measurements, biochemical parameters and free AA profiles were determined.
Results: After the weight loss program, significant changes in body mass and metabolic parameters (e.g., low-density lipoprotein, triglyceride, fasting glucose, and insulin levels) were observed. Positive changes in a homeostatic model assessment of insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) following the program were also found. The levels of 10 AAs (α-amino-n-butyric acid, alanine, citrulline, glutamine, glycine, hydroxyproline, isoleucine, proline, sarcosine, and threonine) had significantly increased following weight loss. Only aspartic acid was present at a significantly lower concentration after the program.
Conclusions: Using a 3-week controlled body mass reduction program based on physical activity and a hypocaloric diet, we were able to demonstrate significant changes in biochemical parameters and free AA profiles. To better understand these changes, future studies should involve a long-term program with more patients.
Keywords: amino acids; body mass reduction; metabolic profile; obesity.