Nutritional consequences of modified vertical gastroplasty in obese subjects

Gastroplasty results in a considerable reduction in food intake and dramatic weight loss. This is likely to have a nutritional impact, although it is expected that this may be minimised by good advice and supplement use.

Twenty six obese subjects were studied in detail before and after modified long vertical gastroplasty (MLVG), in a setting where comprehensive nutritional advice on symptom avoidance was readily available and multivitamin supplements advised. Nutritional intake and anthropometry were measured preoperatively and at 2, 5 (n = 22) and 12 months (n = 11) postoperatively.

Mean weight loss was 13%, 22% and 31% of initial body weight at the respective time points. Energy intake (EI) was significantly reduced postoperatively, with the mean protein intake being only 40 g/d. At 2 months, mean intakes of iron, calcium and zinc from food were 40%, 71% and 39%, respectively, of the Australian recommended dietary intake (RDI), and iron and zinc intake remained below half the RDI at 5 months. Only regular adherence to the vitamin/mineral supplement, brought iron and calcium intakes close to RDI, but zinc remained low. Haemoglobin and serum ferritin concentrations did not alter significantly and remained within the reference range, but serum folate fell significantly between 5 months and 12 months. By 5 months, 60% of subjects never regurgitated or regurgitated less than once a week. Fresh bread was the least tolerated food. Frequency of regurgitation was not correlated with adequacy of nutrient intake.

The results emphasise the need for regular follow-up of MLVG patients, and nutritional advice which includes diet quality as well as symptom management, and regular intake of the vitamin/mineral supplement for at least a year postoperatively. Low protein intakes, however, remain of potential long-term concern.