Research paper
Hollands GJ, Shemilt I, Marteau TM, Jebb SA, Lewis HB, Wei Y, Higgins JPT, Ogilvie D. Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco. Cochrane Database of Systematic Reviews. 2015;(9):CD011045. doi:10.1002/14651858.CD011045.pub2. PMID: 26368271. PMCID: PMC4579823.
Why we cite it
The definitive Cochrane systematic review on portion size — the highest level of evidence synthesis available. Meta-analyzing 72 randomized controlled trials with 6,711 participants, this review establishes that people consistently eat more when given larger portions, packages, or tableware. The effect is small to moderate (SMD 0.38) but practically meaningful: if sustained, eliminating larger portions could reduce daily energy intake by 144-228 kcal (8.5-13.5%). This is the evidence base behind the project's emphasis on environment design — smaller plates, smaller packages, pre-portioned servings — as a strategy that works without requiring conscious effort or willpower. Updated by cpi01 (Hollands et al. 2019) which confirmed the findings with additional evidence.
DOI: 10.1002/14651858.CD011045.pub2 · PubMed 26368271 · Publisher