The majority of studies were observational in nature and showed a reduction in energy intake following surgery , as well as inadequate intakes of micronutrients and protein , and an excessive intake of fats .
There was evidence of nutrient imbalances , suboptimal compliance with multivitamin and mineral supplementation , and limited follow-up of patients .
The current evidence base suggests that despite being effective in reducing energy intake , bariatric surgery can result in unbalanced diets , inadequate micronutrient and protein intakes , and excessive intakes of fats .
In combination with suboptimal adherence to multivitamin and mineral supplementation , this may contribute to nutritional deficiencies and weight regain .
Bariatric surgery is currently the most effective treatment for morbid obesity .
These procedures change the gastrointestinal system with the aim of reducing dietary intake .
Improving diet quality is essential in maintaining nutritional health and achieving long-term benefits from the surgery .
The aim of this systematic review was to examine the relationship between bariatric surgery and diet quality at least 1 year after surgery .
Micronutrient intake, from diet and supplements, and association with status markers in pre- and post-RYGB patients.
BACKGROUND & AIMS Roux-en-Y gastric bypass  ( RYGB ) is associated with an increased risk for micronutrient deficiencies . This study aim ed to assess total ( dietary and supplement ) intake and association with iron ( including hepcidin ) , vitamin B12 , vitamin C and zinc status markers before and after Roux-en-Y gastric bypass ( RYGB ) . METHODS This prospect i ve study included patients with a planned RYGB in University Hospitals Leuven , Belgium ; who were followed until 12 months post-RYGB . Patients completed an estimated dietary record of two non-consecutive days before and 1 , 3 , 6 and 12 months post-RYGB and supplement/drug use was registered . Associations between total micronutrient intake and status markers were analyzed . RESULTS Fifty-four patients ( 21 males ; mean age : 48.0 [ 95%CI 46.6 ; 49.3 ] years ; mean preoperative BMI : 40.4 [ 95%CI 39.4 ; 41.4 ] kg/m2 ) were included . One month post-RYGB , usual dietary intake of the studied micronutrients was significantly decreased compared to pre-RYGB , but gradually increased until 12 months post-RYGB , remaining below baseline values . By including micronutrient supplement intake , 12 months post-RYGB values were higher than baseline , except for zinc . Hemoglobin , ferritin , vitamin B12 and C-reactive protein serum concentrations were significantly decreased and transferrin saturation and mean corpuscular volume were significantly increased 12 months post-RYGB . Serum hepcidin concentration was significantly decreased 6 months post-RYGB . CONCLUSIONS Medical nutritional therapy is essential following RYGB as dietary intake of iron , vitamin B12 , vitamin C , copper and zinc was markedly decreased postoperatively and some patients still had an inadequate total intake one year post-RYGB
The majority of studies were observational in nature and showed a reduction in energy intake following surgery , as well as inadequate intakes of micronutrients and protein , and an excessive intake of fats .
There was evidence of nutrient imbalances , suboptimal compliance with multivitamin and mineral supplementation , and limited follow-up of patients .
The current evidence base suggests that despite being effective in reducing energy intake , bariatric surgery can result in unbalanced diets , inadequate micronutrient and protein intakes , and excessive intakes of fats .
In combination with suboptimal adherence to multivitamin and mineral supplementation , this may contribute to nutritional deficiencies and weight regain .
Bariatric surgery is currently the most effective treatment for morbid obesity .
These procedures change the gastrointestinal system with the aim of reducing dietary intake .
Improving diet quality is essential in maintaining nutritional health and achieving long-term benefits from the surgery .
The aim of this systematic review was to examine the relationship between bariatric surgery and diet quality at least 1 year after surgery .