Impact of dishware size on energy intake in adult females: A randomized control trial examining effects on within-meal and post-meal energy intake.

The influence dishware size has on meal energy intake is unclear and no study to date has examined the impact on total daily energy intake. In a pre-registered RCT we investigate the impact of breakfast dishware size on breakfast and post-breakfast energy intake, as well as daily energy intake and hunger/fullness. In a repeated-measures design, 50 females (aged 18-77 years) were randomised to receive smaller or larger breakfast dishware on two separate days. Energy intake was also measured during the rest of the day. The primary outcomes were breakfast and post-breakfast energy intake (kcal). Secondary outcomes were total daily energy intake (kcal), and hunger/fullness (rated from 0 to 100). We examined if results differed by socioeconomic position (SEP). Dishware did not affect energy intake at breakfast (smaller: M = 394.8 kcal; SD = 172.2 larger: M = 394.4 kcal; SD = 164.4; d = 0.003, p = 0.98), and there was no statistically significant evidence that dishware size affected energy intake after breakfast, though post-breakfast energy intake was somewhat higher after using larger breakfast dishware (smaller: M = 1974.6 kcal; SD = 475.2; larger: M = 2077.5 kcal; SD = 525.9; d = -0.27, p = 0.06). Total daily energy intake, hunger and fullness ratings did not significantly differ between dishware conditions. There was no evidence that SEP moderated the effect of dishware size on energy intake. Smaller vs. larger breakfast dishware size had no significant effect on breakfast or post-breakfast energy intake, hunger, fullness, or daily energy intake. Previous studies may have overestimated the promise of dishware size as an intervention for reducing energy intake. Alternative interventions targeting the food environment should now be prioritised.

Diet Therapy Using a Small Rice Bowl among Japanese Men with Diabetes: A Randomized Controlled Trial.

Background: This study aimed to investigate the effectiveness at 1 and 3 months of using a smaller rice bowl for diet therapy among Japanese men with type 2 diabetes. Methods: A parallel-group randomized controlled trial was conducted at a medical clinic in Japan. The participants were men with type 2 diabetes mellitus, aged 20-80 years, with glycosylated hemoglobin <8.5%, and who ate rice one or more times per day at home. The intervention group (36 men) received a small rice bowl from which to eat the usual diet therapy, and the control group (38 men) received only the usual diet therapy. Results: The changes in weight and body mass index among the intervention group at 1 month were significantly higher than those in the control group. There were no significant differences between the two groups at 3 months. Conclusion: The effects of using a small rice bowl were minor and short-term.

The effects of bowl size and portion size on food intake and fullness ratings in a sample of Japanese men.

OBJECTIVE: Portion sizes and bowl sizes may be related to food intake and perceived fullness. The objective of the present study was to investigate the effects of portion size and bowl size and possible interactions between these variables on food intake and fullness in a sample of Japanese men. DESIGN: Participants ate four different experimental meals across four weeks and completed questionnaires about their fullness using a visual analogue scale administered before and after meals. The four meal patterns included consistent portions of several foods commonly eaten together in typical Japanese meals, along with 150 g of rice served in a small rice bowl (diameter of 11·5 cm), 150 g of rice served in a large rice bowl (diameter of 13·5 cm), 250 g of rice served in a small rice bowl or 250 g of rice served in a large rice bowl. SETTING: Tokyo.SubjectTwenty-one adult men participated in the study. RESULTS: Portion size had a significant main effect on rice intake (F (1,20)=83, P<0·001) and fullness (F (1,20)=8·0, P=0·010), but no significant effects of bowl size on the outcome variables were found. The interactions between portion size and bowl size on intake and fullness were not significant. CONCLUSIONS: The sample of Japanese men showed an influence of portion size on food intake. Further research is needed to clarify the combined effects of bowl size and portion size on intake and fullness.

Difference in Volume Perception of Cooked White Rice according to Size and Color of Rice Bowl in Normal and Obese Women

To examine the effect of obesity on volume perception according to size and color of rice bowl, we divided female college students into a normal weight group ( or =30% fat mass, n=83) and then measured perceived volume of rice bowls of various sizes (general size; 350 ml vs. small size; 188 ml) and color (yellow, white, blue, and black) containing the same amount of cooked white rice (210 g). Normal weight group perceived that the general rice bowl contained significantly more cooked white rice compared to the small rice bowl. In contrast, the obese group perceived that the general rice bowl contained significantly less cooked white rice than the small rice bowl. The estimated variance in perceived volume of both bowls was significantly bigger in the obese group compared to the normal group. There were no differences in perceived volume among any of the subjects (both normal and obese groups) according to rice bowl color. However, the estimated variance in perceived volume in the obese group was significantly larger than that in the normal group for all of the rice bowls. In conclusion, rice bowl size and color might affect volume perception, and volume perception in obese people may be different from that of normal weight people.