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 and Protein Deficiencies After Gastric Bypass and Sleeve Gastrectomy: a 1-year Follow-up
Background Roux-en-Y gastric bypass ( GBP ) and sleeve gastrectomy ( SG ) have increased dramatically , potentially increasing the prevalence of nutritional deficiencies . The aim of this study was to analyze the effects of food restriction during the first year after  bariatric surgery ( BS ) on nutritional parameters . Methods Twenty-two and 30 obese patients undergoing GBP and SG  were prospect ively followed at baseline and 3 , 6 , and 12 months after BS ( N = 14 and N = 19 at T12 ) . We evaluated food intake and nutrient adequacy ( T0 , T3 , T12 ) , as well as serum vitamin and mineral concentration ( T0 , T3 , T6 , T12 ) . Results At baseline , GBP and SG patients had similar clinical characteristics , food intake , nutrient adequacy , and serum concentration . The drastic energy and food reduction led to very low probabilities of adequacy for nutrients similar in both models ( T3 , T12 ) . Serum analysis demonstrated a continuous decrease in prealbumin during the follow-up , indicating mild protein depletion in 37 and 38 % of GBP patients and 57 and 52 % of SG patients , respectively , at T3 and T12 . Conversely , despite the low probabilities of adequacy observed at T3 and T12 , systematic multivitamin and mineral supplementation after GBP and SG prevented most nutritional deficiencies . Conclusions GBP and SG have comparable effects in terms of energy and food restriction and subsequent risk of micronutrient and protein deficiencies in the first year post BS . Such results advocate for a cautious monitoring of protein intake after GPB and SG and a systematic multivitamin and mineral supplementation in the first year after SG
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 .