Cold induces increased ad libitum energy intake independent of changes in energy expenditure: a controlled crossover trial in adults.
Level 2 - randomized trial
Randomized controlled crossover trial
PubMed 39675563 · doi:10.1016/j.ajcnut.2024.12.013
What was done
In a controlled crossover trial, 47 adults (16 female; mean age 37.2 ± 10.7 years; mean BMI 32.4 ± 8.6 kg/m²) completed four 24-hour stays in a respiratory chamber. Energy expenditure (EE), respiratory exchange ratio (RER), and carbohydrate oxidation (CARBOX) were evaluated during eucaloric stays under mild cold (19°C) and thermoneutral (23.5°C) conditions. Ad libitum energy intake (EI) was assessed during 24-hour cold and thermoneutral chamber stays using an automated vending machine paradigm, as well as on the day following each exposure.
What was found
During cold exposure, participants consumed 13% more energy compared with thermoneutral conditions (mean difference: 411 ± 987 kcal/d, P = 0.006). Ad libitum EI was not increased on the day following cold exposure. Mild cold did not significantly alter eucaloric 24-hour EE, RER, or CARBOX, and cold-induced EE changes did not correlate with changes in EI. However, higher RER (r = 0.29, P = 0.049) and CARBOX (r = 0.33, P = 0.02) during cold exposure were associated with greater ad libitum EI on the subsequent day.
Why it matters
This study provides causal evidence that mild cold exposure can acutely stimulate food intake independently of an increase in metabolic rate, challenging the assumption that cold-induced hyperphagia is purely driven by increased energy expenditure.
Limits
The sample was modest (n = 47) and exhibited substantial individual variance in intake response (SD ± 987 kcal/d). The findings reflect short-term acute 24-hour exposure to 19°C in a confined respiratory chamber environment, which may not generalise to chronic cold exposure or free-living dietary behaviour.
Cited by
- context Mild cold stress naturally lowers the respiratory quotient (RQ), shifting substrate utilization toward fat oxidation.