Acceptance, impact and mechanisms of action of portion control tools for the management of body weight in adults

Resumen

Exposure to large portion sizes (PSs), especially from high energy dense foods and sugar-sweetened beverages (SSBs), has been related with energy overconsumption and the promotion of obesity. The use of portion control tools has been proposed as a potentially effective strategy to counteract these trends, however, the specific mechanisms by which these tools work are still unclear. The objectives of this work were: (i) to evaluate the breadth, impact and acceptance of existing portion control tools; (ii) to elucidate the behavioural and physiological processes involved in PS control; (iii) to address existing gaps in eating behavior research particularly related to PS mechanisms. A systematic review was conducted to describe the variety and effectiveness of existing portion control tools for foods/beverages on awareness of appropriate PSs, PS choice and PS consumption using a meta-analytic approach. Results confirmed an overall effect of tools on food intake, mostly driven by combinations of reduced-size bowls and spoons decreasing serving sizes and consumed amounts/energy, but not by reduced-size plates. Portion control tools marginally induced weight loss, especially calibrated tableware. Secondly, a new combined methodological platform, designed to measure different eating behavior metrics under controlled laboratory conditions was developed and validated. The novel platform showed a significant improvement in meal micro-structural parameters from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.92). The combined platform was subsequently used in a laboratory intervention to explore the mechanisms by which a portion control plate (calibrated with visual guides for starch, protein and vegetables) modulated food intake, satiety and meal eating behavior in women. Compared with a control plate, the calibrated plate reduced meal sizes of a lunch buffet including rice, vegetables and meatballs. The calibrated plate also reduced bite size and tended to reduce eating rate of the meal. Despite overall good effectiveness (66%), about half of the women providing valid food records and responding to the calibrated design (n=10/19) compensated the reduced intake over the 8 h following the meal. Post-prandial pancreatic polypeptide concentrations were higher with the calibrated plate. The longest gaze fixation during the first minute of the meal across all foods was on the vegetables irrespective of the plate used. This longer fixation was associated with a tendency for lower hunger and higher fullness feelings immediately and 3h post-meal consumption. Finally, an on-line survey was developed and administered to 166 adults to explore PS awareness and consumption habits of SSBs. The results showed that a large proportion of participants (66%) perceived the use of an educational portion control tool for SSBs as useful. Across a range of eight tools, a calibrated glass was the most preferred tool to try, in conjunction with an interactive virtual tool which was perceived as the preferred tool for medium term use. Portion control tools, mainly calibrated tableware, serving utensils and technology-based tools, were identified as having the potential to guide food PS and modulate consumption. Specifically, a tested and validated portion control plate, may improve meal eating habits and might modulate the cephalic-phase satiety response. The new survey helped identify that portion control tools potentially providing immediate feedback, such as calibrated and interactive virtual tools, are likely to be the best accepted and used by the public.