Does Melatonin Increase Night Eating?
No, melatonin does not increase night eating; in fact, evidence suggests it may help regulate appetite and reduce food intake, though its metabolic effects appear to occur independently of changes in energy consumption.
Evidence on Melatonin and Eating Behavior
The relationship between melatonin and eating habits has been systematically evaluated, with findings indicating that melatonin supplementation does not promote nocturnal food intake:
A systematic review of randomized controlled trials found that exogenous melatonin supplementation may help restore homeostasis in appetite regulation, particularly when circadian disruption has led to excessive food consumption 1
The metabolic effects of melatonin appear to occur independently of energy intake, meaning that any beneficial metabolic changes are not necessarily associated with alterations in food consumption patterns 1
Melatonin's primary physiological function is to convey information about the daily light-dark cycle to body structures, helping organize circadian rhythms including those related to glucose regulation and metabolic function 2
Melatonin's Role in Sleep and Circadian Regulation
Understanding melatonin's mechanism clarifies why it would not increase night eating:
Melatonin is naturally secreted by the pineal gland at night and serves as a biochemical signal of darkness, helping to organize circadian rhythms including sleep-wake cycles 2
Low oral doses (0.3-1.0 mg) given in the evening decrease sleep onset latency and facilitate sleep without causing hangover effects or altering sleep architecture 3, 4
The hormone's sleep-promoting effects occur when serum concentrations reach normal nocturnal physiologic ranges, typically 2-4 hours before habitual bedtime 4
Clinical Guidelines on Melatonin Use
Current guidelines support melatonin's safety profile without mentioning increased eating as a concern:
The American Academy of Sleep Medicine's 2017 clinical practice guideline found no clinically significant differences in adverse events between melatonin and placebo across various dosages and durations 5
The 2008 guideline noted that melatonin has small effects on sleep latency with little effect on wake after sleep onset or total sleep time, but did not identify increased appetite or night eating as adverse effects 5
For elderly patients, melatonin has a favorable safety profile with minimal adverse effects reported, and unlike benzodiazepines, it is not listed on potentially inappropriate medication lists 6, 7
Important Clinical Considerations
When prescribing melatonin, be aware of these factors:
Dietary factors can modulate melatonin levels, but the influence of daytime diet on nocturnal melatonin synthesis is limited 8
Melatonin is synthesized from tryptophan, and nutritional factors including vitamins and minerals needed as cofactors may affect melatonin production 8
Caution is advised when prescribing to patients taking warfarin and to patients with epilepsy due to potential interactions 9, 6
Lower doses may be more effective than higher doses due to potential receptor desensitization, and higher doses are associated with morning grogginess 9, 7