Changes in nutrient composition and diet quality in the first 6 months following bariatric surgery: An observational cohort study

Background Bariatric surgery (BS) may result in inadequate nutrient intake and poor diet quality, which can lead to nutritional complications. The present study aimed to evaluate changes in macro- and micronutrient composition and diet quality in the first 6 months following BS.Methods One hundred seven participants undergoing BS (Roux-en-Y gastric bypass: n = 87, sleeve gastrectomy: n = 20) completed 3-day food records before and 6 months after surgery. Changes in energy, macronutrient (carbohydrates, protein, fat, dietary fibre) and micronutrient intake (folate, vitamin B12, vitamin D, calcium, iron) were evaluated. Diet quality was assessed by adherence to the Dutch food-based dietary guidelines.Results After BS, we observed a significant decrease in intake of energy and all macro- and micronutrients (p < 0.01 for all), except for calcium (-39.0 +/- 404.6 mg; p = 0.32). Overall, nutrient composition slightly changed with an increase in the relative intake of protein (+1.1 +/- 4.3 energy percentage [en%]; p = 0.01) and mono- and disaccharides (+4.2 +/- 6.4 en%; p < 0.001) post-surgery. Consumption (median [Q1, Q3]) of vegetables (-50 [-120, 6] g day(-1)), wholegrain products (-38 [-81, -8] g day(-1)), liquid fats (-5 [-13, 2] g day(-1)), red meat (-3 [-30, 4] g day(-1)), processed meat (-32 [-55, 13] g day(-1)), sodium (-0.7 [-1.1, -0.2] g day(-1)) and unhealthy food choices (-2.4 [-5.0, 0.6] serves week(-1)) significantly decreased after BS (p < 0.01 for all).Conclusions Our results demonstrate both favourable and unfavourable changes in macro- and micronutrient composition and diet quality in the first 6 months following BS. Insight into these changes can improve dietary counselling in this population. Future research into underlying causes, consequences and long-term changes in dietary intake is needed.