Bariatric surgery has significantly increased globally as an effective treatment for severe obesity. Nutritional deficits are common among candidates for bariatric surgery, and follow-up of nutritional status is critically needed for post-surgery healthcare management. This observational prospective study was conducted at King Khalid University Hospital in Riyadh. Samples were collected pre- and post-laparoscopic sleeve gastrectomy (LSG), with the visit intervals divided into four visits: pre-surgery (0M), 3 months (3M), 6 months (6M) and 12 months (12M). Food intake and eating patterns significantly changed during the first year (P < 0·001). The mean energy intake at 3M post-surgery was 738·3 kcal, significantly lower than the pre-surgery energy intake of 2059 kcal. Then, it increased gradually at 6M and 12M to reach 1069 kcal (P < 0·00). The intake of Fe, vitamin B12 and vitamin D was below the dietary reference intake recommendations, as indicated by the 24-hour dietary recall. The prevalence of 25 (OH) vitamin D deficiency improved significantly from pre- to post-surgery (P < 0·001). Vitamin B12 deficiency was less reported pre-LSG and improved steadily towards a sufficient post-surgery status. However, 35·7 % of participants were deficient in Fe status, with 28·6% being female at higher levels than males. While protein supplementation decreased significantly over the 12M follow-up, the use of vitamin supplements dramatically increased at 3 and 6M before declining at 12M. Fe and vitamin B12 were the most popular supplements after vitamin D. This study confirms the necessity for individualised dietary plans and close monitoring of candidates' nutritional status before and after bariatric surgery.
Keywords: Bariatric surgery; Nutritional status; Sleeve gastrectomy; Vitamin deficiencies.