On optimal nutrition after weight reduction surgery
Bariatric surgery (BS) procedures including gastric bypass surgery are the most effective therapy for weight loss and for treatment of comorbidities associated with obesity. Moreover, surgical complications are rare. However, vitamin, mineral and protein deficiencies may develop, and there are no evidence-based dietary recommendations for use during calorie restriction. Dietary protein (PRO) maintains lean body mass and promotes weight maintenance but may encourage insulin resistance. The EU funded MIPS (Metabolic impact of dietary protein supplementation in surgical weight loss) project tested standard and high levels of PRO supplementation after BS. Long term weight gain and low protein are common after BS and there are no defined dietary protein supplementation recommendations. Trial design incorporated many factors, some extremely important to long-term patient welfare. Parameters taken into account were the carry-over effect of the intervention at nine months as well as the safety and effect of PRO supplementation during weight loss on glucose homeostasis, satiety, nitrogen balance, lean body mass preservation, and total daily energy expenditure. The researchers also considered other crucial issues including the quantity of protein supplementation and its duration after BS. Weight regain is due to many factors. These include inappropriate lifestyle, lower resting energy expenditure, loss of fat free mass (FFM), and in addition, metabolic variables such as changes in intestinal flora and inflammatory cytokines. The randomised pilot study collected data on the effect of weight loss and PRO supplementation with nitrogen balance, lean body and fat mass as well as total body water. An after-meal test involved measuring resting energy expenditure, diet induced thermogenesis, as well as the gut hormones (peptide tyrosine-tyrosine and glucagon-like peptide 1) that may reduce food intake. Perceived satiety and serum levels of branched chain amino acids were also assessed. MIPS has designed and validated a rigorous method to examine the variables that influence a patient’s health after BS with particular focus on long-term weight gain. Project members propose a follow-up MIPS randomised control trial with a higher number of subjects. Future results could significantly contribute to drawing up of evidence-based nutritional guidelines for the clinical management of BS patients under short and long-term follow-up.
Keywords
Weight loss surgery, PRO, MIPS, weight gain, randomised control trial
