Food photography .2. Use of food photographs for estimating portion size and the nutrient content of meals
Food photography .2. Use of food photographs for estimating portion size and the nutrient content of meals
复制标题
DOI：
10.1079/bjn19960007
复制
发表时间：
1996-07-01
影响因子：
3.6
通讯作者：
Darbyshire, S
中科院分区：
文献类型：
--
作者：
Nelson, M;Atkinson, M;Darbyshire, S
本研究的目的是确定错误的概念化部分大小使用照片。来自各种社会和职业背景的18-90岁的男性和女性志愿者（n 136）完成了602份与食物照片有关的份量评估。受试者在一顿饭（早餐，午餐或晚餐）中吃四到六种食物。研究人员在上菜时称量了份量，在用餐结束时称量了任何废物。在用餐结束后的5分钟内，向受试者展示描述刚刚消耗的每种食物的照片。对于每种食物，有8张照片显示了在英国成人饮食和营养调查中观察到的部分重量分布的第5至第95百分位数的等增量部分大小（Gregory等人，1990）。受试者被要求在视觉模拟量表上指出与八张照片相关的消耗部分的大小。膳食的营养素含量估计从食物组成表。有很大的变化，估计部分大小从照片。黄油和人造黄油的份量往往被大大高估。一般来说，小部分的大小往往被高估，大部分的大小被低估。老年人高估部分大小往往比年轻的科目。不包括黄油和人造黄油，基于估计份量的膳食营养素含量平均在基于消耗量的营养素含量的+/-7%范围内，除了维生素C（21%高估）和65岁以上的受试者（15-20%高估能量和脂肪）。在BMI小于2 - 5 kg/m2的受试者中，根据食物成分表和估计的份量（不包括黄油和人造黄油）计算的膳食能量和脂肪含量比使用实际份量计算的营养素含量高5-10%，但对于BMI 30 kg/m2或以上的受试者，计算的能量和脂肪含量被低估了2- 5%。膳食营养素含量与实际或估计份量的相关性在0.84至0.96之间。对于能量和八种营养素，69%至89%的受试者被正确地分类到三分之一的摄入量分布使用估计的部分大小相比，摄入量的基础上，实际部分大小。当“平均”份量（受试者自己提供的每种食物的平均重量）被用来代替基于照片的估计时，正确分类的受试者人数下降到60%到79%之间。我们报告的第一次错误与概念化和膳食的营养成分时，使用照片来估计食物的份量。我们的结论是，照片描绘了一系列的部分大小是一个有用的援助估计部分大小。与使用平均份量相比，使用照片来估计份量时，根据一餐的营养摄入量对受试者进行错误分类的情况减少了。当使用照片估计食物消耗或营养摄入时，年龄、性别、BMI和份量都是潜在的重要混杂因素。
The aim of the present study was to determine the errors in the conceptualization of portion size using photographs. Male and female volunteers aged 18-90 years (n 136) from a wide variety of social and occupational backgrounds completed 602 assessments of portion size in relation to food photographs. Subjects served themselves between four and six foods at one meal (breakfast, lunch or dinner). Portion sizes were weighed by the investigators at the time of serving, and any waste was weighed at the end of the meal. Within 5 min of the end of the meal, subjects were shown photographs depicting each of the foods just consumed. For each food there were eight photographs showing portion sizes in equal increments from the 5th to the 95th centile of the distribution of portion weights observed in The Dietary and Nutritional Survey of British Adults (Gregory et al. 1990). Subjects were asked to indicate on a visual analogue scale the size of the portion consumed in relation to the eight photographs. The nutrient contents of meals were estimated from food composition tables. There were large variations in the estimation of portion sizes from photographs. Butter and margarine portion sizes tended to be substantially overestimated. In general, small portion sizes tended to be overestimated, and large portion sizes underestimated. Older subjects overestimated portion size more often than younger subjects. Excluding butter and margarine, the nutrient content of meals based on estimated portion sizes was on average within +/-7% of the nutrient content based on the amounts consumed, except for vitamin C (21% overestimate), and for subjects over 65 years (15-20% overestimate for energy and fat). In subjects whose BMI was less than 25 kg/m(2), the energy and fat contents of meals calculated from food composition tables and based on estimated portion size (excluding butter and margarine) were 5-10% greater than the nutrient content calculated using actual portion size, but for those with BMI 30 kg/m(2) or over, the calculated energy and fat contents were underestimated by 2-5%. The correlation of the nutrient content of meals based on actual or estimated portion sizes ranged from 0.84 to 0.96. For energy and eight nutrients, between 69 and 89% subjects were correctly classified into thirds of the distribution of intake using estimated portion size compared with intakes based on actual portion sizes. When 'average' portion sizes (the average weight of each of the foods which the subjects had served themselves) were used in place of the estimates based on photographs, the number of subjects correctly classified fell to between 60 and 79%. We report for the first time the error associated with conceptualization and the nutrient content of meals when using photographs to estimate food portion size. We conclude that photographs depicting a range of portion sizes are a useful aid to the estimation of portion size. Misclassification of subjects according to their nutrient intake from one meal is reduced when photographs are used to estimate portion size, compared with the use of average portions. Age, sex, BMI and portion size are all potentially important confounders when estimating food consumption or nutrient intake using photographs.