Table 1 Studies into the effects of portion size on food intake

Diliberti,2004 [12]

Between subjects, parallel group design, with two different portion sizes (100%^a, 152%)

Cafeteria visitors at a university campus, n = 180

Baked pasta in cheese sauce (54% fat, energy density 1.7 kcal/g)

-Increased energy intake when served a larger portion, 43% more (172 kcal)

-Overall extra energy intake of entire meal 25% (172 kcal)

Fisher, 2007 [13]

Within subjects cross over design, with two different portion sizes (100%^a, 200%)

Low income Hispanic and African American mothers, n = 58

Macaroni & cheese (1.51 kcal/g), apple juice (0.47 kcal/g), crackers (4.62 kcal.g), chicken (1.73–2.42 kcal/g), rice (0.8 kcal/g), cereal (4.0 kcal/g)

-Increased energy intake when served a larger portion, 21% more (270 kcal), over 24 hour period

Flood, 2006 [14]

Within subjects cross over design, with two different portion sizes (100%^a, 150%) (and three different beverages)

Adults, n = 33 (aged 18–45)

Beverages (regular cola (0.4 kcal/g), diet cola, water)

-Increased beverage intake when served a larger portion, 10% more for women, 26% for men (regular cola)

Kral, 2004 [15]

Within subjects cross over design, with three different portion sizes (100%^a, 140%, 180%) (and three different energy densities)

Women (aged 20–45), n = 39

Italian pasta bake (25% fat, 60% carbohydrate, 15% protein, 1.25 kcal/g–1.75 kcal/g)

-Increased food intake when served a larger portion, 20% more food intake when served the largest portion compared to the smallest portion

-Combined effect with energy density: 56% more energy intake when served the largest higher energy dense portion compared to the smallest lower energy dense portion (225 kcal)

Raynor, 2007 [16]

Random 2(small amount or large amount, 100%^a, 200%) × 2 (small unit or large unit) between subjects design

Adults (aged 18–30), n = 28

Potato chips, cheese crackers, cookies, candy

-Increased energy intake when served a larger portion, 81% (2246 kcal), over three day period

-No effect of package unit size

Rolls, 2002 [17]

Within subjects cross over design, with four different portion sizes (100%^a,125%, 150%, 200%)

Adults (aged 21–40), n = 51

Macaroni & cheese (1.63 kcal/g)

-Increased energy intake when served a larger portion (resp. 12% more (64 kcal), 19% more (105 kcal), and 30% more (161 kcal)

Rolls, 2004 [18]

Within subjects cross over design, with five different portion sizes (100%^a, 150%, 204%, 357%, 507%)

Adults (aged 20–45), n = 60

Potato chips (5.4 kcal/g)

-Increased energy intake when served a larger portion, 184 kcal more for women when comparing largest vs smallest portion, for men 311 kcal

-No short term compensation at dinner

Rolls, 2004 [19]

Within subjects cross over design, with four different portion sizes (100%^a, 134%, 167%, 200%)

Adults (aged 20–45), n = 75

Deli-style sandwich, (2.4 kcal/g)

-Increased energy intake when served a larger portion, 31% more for women when comparing largest vs smallest portion(159 kcal), for men 56% more (355 kcal)

Rolls, 2006 [20]

Within subjects cross over design, with three different portion sizes (100%^a, 150%, 200%)

Adults (aged 19–45), n = 32

Complete daily menu (varying from 0.2 kcal/g (vegetable side dish) to 5.5 kcal/g (snack foods)

-Increased energy intake when served larger portions, for all food categories, resp. 16% more (women 335 kcal/day, men 504 kcal/day) and 26% more (women 530 kcal/day, men 812 kcal/day)

-No compensation over two day time period

Rolls, 2007 [21]

Within subjects cross over design, with two different portion sizes (100%^a, 150%)

Adults (aged 20–40), n = 23

Complete daily menu, each day different

-Increased energy intake when served larger portions, for all food categories except fruit as afternoon snack and vegetables, average increase in energy intake 423 kcal/day

-No compensation over 11-day time period

Wansink, 2001 [22]

2 (medium or large container, 100%^a, 200%) × 2(perceived favourable vs unfavourable taste) between subjects design

Moviegoers (aged 11–89), n = 151

Popcorn

-Increased food intake when served a larger portion, for both perceived favourable and unfavourable taste, 53% more

Wansink, 2005 [23]

Random 2 (medium or large container, 100%^a, 200%, × 2 (fresh or stale) between subjects design

Adult moviegoers, n = 158

Fresh and stale popcorn

-Increased food intake when served a larger portion, for both fresh and stale popcorn, resp. 45% and 34%

Wansink, 2005 [24]

Random between subjects, parallel group design (normal bowl vs self refilling bowl)

Adults (ages 18–46), n =

Soup

-Increased energy intake when served a larger portion without accurate visual cue, 73% more (113 kcal)