Nudge150: Combining small changes to foods to achieve a sustained decrease in energy intake

实现持续减少能量（食物）摄入是保持健康体重和对抗超重和肥胖的关键。该项目结合了两种方法来应对这一挑战。第一个原因是人体对能量平衡没有严格的生理控制。虽然这是我们容易暴饮暴食的原因，但也意味着我们可以在不感到无法抗拒的饥饿感的情况下减少食物摄入量。研究发现，如果人们在一餐中吃得不足，那么他们在随后的几餐中增加的食量并不能完全弥补。所以，如果我们每天少吃150千卡的午餐，一年下来，我们可能会少吃18000千卡（365 x 50千卡），这将有助于防止体重增加，甚至可能导致轻微的体重减轻。这种注重减少份量的做法与英国政府的“责任协议”和其他国家的公共卫生倡议是一致的。我们将在这个项目中测试这种-150千卡的“推动”饮食行为的可行性。我们还将调查我们所吃食物的各种额外的小推动的有效性，旨在提高减少份量推动的有效性和长期可接受性（可能导致每天自发减少100千卡的食物摄入量）。一个显而易见的方法是增加食物的饱腹感，但这已经在各种研究中进行了尝试，但收效甚微。相反，我们将研究增加用餐“满意度”的方法，并测试这是否有助于控制食欲——我们的方法是“奖励你的食欲”，而不是“更长时间地感到饱腹”。“因此，在研究的第一阶段，我们将调查，例如，增加口味强度，增加食物种类，改变食物质地（例如，奶油与耐嚼）和单位大小（例如，相同的食物以大量的小块呈现）是否会提高用餐满意度并降低随后的食欲。”在初步研究中，我们还将邀请消费者和食品行业专家对这些方法发表评论，并帮助我们产生其他可供测试的想法。我们还将研究减少份量的“断点”；也就是说，人们在什么情况下会选择补充食物，甚至是两份食物？我们将根据广泛用于测量其他人类感知能力的既定原则开发一种方法来做到这一点。在研究的第二阶段，我们将比较(1)标准午餐，(2)相同午餐的较小部分（-150千卡），以及(3)较小的午餐（也是-150千卡）对随后食欲和能量摄入的影响，并结合最可行和最有效的提高用餐满意度的操作。这将在10次（第1、3和10天）接触这些午餐的开始和结束时进行，以测试可能随着时间的推移降低这些“轻推”效果的适应效应。这项研究的影响在于创新地测试了-150千卡推动的短期和长期有效性，并强调膳食满意度是一种有希望的方式，可以帮助人们持续接受（稍微）较小的份量，从而为食品行业提供了一条途径，帮助实施广泛支持的公共卫生体重管理方法。

Achieving sustained decreases in energy (food) intake is key to maintaining healthy weight and combating overweight and obesity. This project combines two approaches to meet this challenge. The first of these arises from the fact that there is not tight physiological control of energy balance. While this underlies our vulnerability to overeating, it also means that it is possible to reduce our food intake without experiencing irresistible hunger. It has been found that if people under-eat at one meal, they do not fully compensate with increased eating at subsequent meals. So, if we ate 150 kcal less at lunch every day for a year we might expect to eat 18,000 kcal (365 x 50 kcal) less over that year, which would help to prevent weight gain, or might even cause slight weight loss. This focus on reduced portion size is consistent with the UK Government's 'Responsibility Deal' and public health initiatives in other counties.We will test the feasibility of this -150 kcal 'nudge' to eating behaviour in this project. We will also investigate the effectiveness of various additional small nudges to the foods we eat aimed at increasing the effectiveness and long-term acceptability of the reduced portion size nudge (perhaps leading to up to a spontaneous 100 kcal per day reduction in food intake). An obvious approach would be to try to increase the fillingness of foods, but this has been tried in a variety of studies and has met with limited success. Instead we will investigate ways to increase meal 'satisfaction' and test whether this helps to control appetite - our approach here is 'reward your appetite,' rather than 'feel fuller for longer.'Accordingly, in the first phase of the research we will investigate whether, for example, increasing taste intensity, increasing food variety, and modifying food texture (e.g., creamy versus chewy) and unit size (e.g., same item presented in a larger number of smaller pieces) will enhance meal satisfaction and reduce subsequent appetite. In preliminary studies we will also invite consumers and food industry experts to comment on these approaches and help us generate other ideas to test. We will also investigate the 'breakpoint' in portion size reduction; that is, at what point do people choose supplementary items or even two portions? We will develop a method to do this based on established principles used widely in the measurement of other human perceptual abilities.In the second phase of the research we will compare the effect on subsequent appetite and energy intake of (1) a standard lunch, (2) a smaller portion of the same lunch (-150 kcal), and (3) a smaller lunch (also -150 kcal) combined with a blend of the most feasible and effective manipulations for increasing meal satisfaction. This will be done at the beginning and end of ten exposures (days 1, 3 and 10) to these lunches to test for possible adaptation effects that might reduce the effectiveness of these 'nudges' over time. The impact of this research lies in the innovation testing the short and longer term effectiveness of the -150 kcal nudge, and in emphasising meal satisfaction as a promising way to aid sustained acceptance of (slightly) smaller portion sizes, thereby providing a route for the food industry to help implement a widely supported public health approach to weight management.