The only properly design ed , low bias and highly powered study found a weight increasing effect  of dronabinol in AN , while the other , using Δ9-THC at a high dose , found no effect and where the dose may have counteracted the weight gaining effects due to adverse events .
Anorexia nervosa ( AN ) is a psychiatric disorder with a high mortality and unknown etiology , and effective treatment is lacking .
For decades , cannabis has been known to cause physical effects on the human body , including increasing appetite , which may be beneficial in the treatment of AN .
To systematic ally review the literature for evidence of an effect of cannabinoids on ( 1 ) weight gain , and ( 2 ) other outcomes , in AN .
Effect of dronabinol therapy on physical activity in anorexia nervosa: a randomised, controlled trial
Purpose The level of physical activity is inappropriately high in up to 80 % of the patients suffering of anorexia nervosa ( AN ) , as a result of conscious efforts to lose weight , affect regulation and biological adaptive changes to starvation induced by hypothermia and neuroendocrine mechanisms . The purpose s of this paper were to ( 1 ) assess the effect of dronabinol — a synthetic cannabinoid agonist — on physical activity in patients with chronic and stable AN , and to ( 2 ) unravel the role of leptin and cortisol in this process . Methods This prospect i ve , r and omised , double-blind , crossover study was conducted at a specialised care centre for eating disorders . Twenty-four adult women with AN of at least 5-year duration received either the dronabinol-placebo or placebo-dronabinol sequence .  Physical activity was monitored during the fourth week of each intervention . Body weight , leptin and urinary free cortisol excretion were measured repeatedly during the trial . Changes in behavioural dimensions related to AN were assessed by Eating Disorder Inventory-2 . Results The total duration of physical activity did not change , while its average intensity increased by 20 % ( P = 0.01 ) during dronabinol therapy , result ing in an increased energy expenditure with 68.2 kcal/day ( P = 0.01 ) above placebo . Conclusions This r and omised , double-blind study revealed that cannabinoid agonist treatment was associated with a modest increase in physical activity in adult women with severe and longst and ing AN . Additionally , we detected a strong relationship between the circulating levels of leptin and physical activity in these chronically undernourished patients
The only properly design ed , low bias and highly powered study found a weight increasing effect  of dronabinol in AN , while the other , using Δ9-THC at a high dose , found no effect and where the dose may have counteracted the weight gaining effects due to adverse events .
Anorexia nervosa ( AN ) is a psychiatric disorder with a high mortality and unknown etiology , and effective treatment is lacking .
For decades , cannabis has been known to cause physical effects on the human body , including increasing appetite , which may be beneficial in the treatment of AN .
To systematic ally review the literature for evidence of an effect of cannabinoids on ( 1 ) weight gain , and ( 2 ) other outcomes , in AN .