Nutritional intervention to prevent weight gain in patients commenced on olanzapine: a randomized controlled trial.
OBJECTIVE
Olanzapine is the most commonly prescribed atypical antipsychotic medication in Australia. Research reports an average weight gain of between 4.5 and 7 kg in the 3 months following its commencement. Trying to minimize this weight gain in a population with an already high prevalence of obesity, mortality and morbidity is of clinical and social importance. This randomized controlled trial investigated the impact of individual nutrition education provided by a dietitian on weight gain in the 3 and 6 months following the commencement of olanzapine.


METHODS
Fifty-one individuals (29 females, 22 males) who had started on olanzapine in the previous 3 months (mean length of 27 days +/- 20) were recruited through Peninsula Health Psychiatric Services and were randomly assigned to either the intervention (n = 29) or the control group (n = 22). Individuals in the intervention group received six 1 hour nutrition education sessions over a 3-month period. Weight, waist circumference, body mass index (BMI) and qualitative measures of exercise levels, quality of life, health and body image were collected at baseline at 3 and 6 months.


RESULTS
After 3 months, the control group had gained significantly more weight than the treatment group (6.0 kg vs 2.0 kg, p < or = 0.002). Weight gain of more than 7% of initial weight occurred in 64% of the control group compared to 13% of the treatment group. The control group's BMI increased significantly more than the treatment group's (2 kg/m(2)vs 0.7 kg/m(2), p < or = 0.03). The treatment group reported significantly greater improvements in moderate exercise levels, quality of life, health and body image compared to the controls. At 6 months, the control group continued to show significantly more weight gain since baseline than the treatment group (9.9 kg vs 2.0 kg, p < or = 0.013) and consequently had significantly greater increases in BMI (3.2 kg/m(2)vs 0.8 kg/m(2), p < or = 0.017).


CONCLUSIONS
Individual nutritional intervention provided by a dietitian is highly successful at preventing olanzapine-induced weight gain.
Evans
Sherryn
S
Peninsula Health, Department of Nutrition and Dietetics, Frankston Hospital, PO Box 52, Frankston, Victoria 3199, Australia. sevans@phcn.vic.gov.au
Newton
Richard
R
Higgins
Sally
S
D000328:Adult; D001569:Benzodiazepines / Q000009:adverse effects / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy*; D001828:Body Image; D015992:Body Mass Index; D003865:Major Depressive Disorder / Q000188:drug therapy*; D015444:Exercise; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D009747:Nutritional Physiological Phenomena; D009765:Obesity / Q000139:chemically induced / Q000178:diet therapy / Q000517:prevention & control; D000077152:Olanzapine; D011788:Quality of Life; D012559:Schizophrenia / Q000188:drug therapy*; D015430:Weight Gain
D001569:Benzodiazepines; D000077152:Olanzapine