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 .
Long-term dietary intake and nutritional deficiencies following sleeve gastrectomy or Roux-En-Y gastric bypass in a mediterranean population.
BACKGROUND Data on long-term dietary changes and nutritional deficiencies after  sleeve gastrectomy ( SG ) in grade 3 obese patients are scarce . OBJECTIVE To prospect ively compare dietary changes and nutritional deficiencies in grade 3 obese patients 5 years after SG and Roux-en-y gastric bypass ( GBP ) .  PARTICIPANTS / SETTING Three hundred and fifty-five patients who had SG ( n=61 ) or GBP ( n=294 ) ( May 2001-December 2006 ) at a Spanish university hospital . DESIGN Longitudinal , prospect i ve , observational study . PRIMARY OUTCOMES /STATISTICAL ANALYSES : Changes in energy , macronutrient , and micronutrient intake , and weight loss were analyzed using mixed models for repeated measurements . RESULTS At the 5-year follow-up visit , the percentage of excess weight loss ( P=0.420 ) and daily energy intake ( P=0.826 ) , as well as the proportion of energy from carbohydrates ( P=0.303 ) , protein ( P=0.600 ) , and fat ( P=0.541 ) did not differ between surgical groups . Energy intake ( P=0.004 ) , baseline weight ( P<0.001 ) , and time period ( P<0.001 ) , but not the proportion of different macronutrients or the type of surgery , independently predicted the percentage excess weight loss over time . After SG or GBP , the mean daily dietary intake of calcium , magnesium , phosphorus , and iron was less than the current recommendations . Despite universal supplementation , the prevalence of nutritional deficiencies was comparable after SG or GBP , with 25-hydroxyvitamin D being the most commonly observed deficiency ( SG , 93.3 % to 100 % ; GBP , 90.9 % to 85.7 % , P = not significant ) . In an adjusted multivariate regression model , energy intake and lipid intake independently predicted plasma 25(OH)-vitamin D levels . CONCLUSIONS Data show that SG and GBP are associated with similar long-term weight loss with no differences in terms of dietary intake . Furthermore , data demonstrate that both types of surgeries carry comparable nutritional consequences
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 .