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At least 19 recordsLinked to original sources
PubMed2000

Comparison of a dietary record using reported portion size versus standard portion size for assessing nutrient intake.

OBJECTIVE: Because the percentage of missing portion sizes was large in the Aerobics Center Longitudinal Study (ACLS), careful consideration of the accuracy of standard portion sizes was necessary. The purpose of the present study was to investigate the consequences of using standard portion sizes instead of reported portion sizes on subjects' nutrient intake. METHODS: In 2307 men and 411 women, nutrient intake calculated from a 3-day dietary record using reported portion sizes was compared with nutrient intake calculated from the same record in which standard portion sizes were substituted for reported portion sizes. RESULTS: The standard portion sizes provided significantly lower estimates (>/= 20%) of energy and nutrient intakes than the reported portion sizes. Spearman correlation coefficients obtained by the two methods were high, ranging from 0.67 to 0.93. Furthermore, the agreement between both methods was fairly good. Thus, in the ACLS the use of standard portion sizes rather than reported portion sizes did not appear to be suitable to assess the absolute intake at the group level, but appeared to lead to a good ranking of individuals according to nutrient intake. These results were confirmed by the Continuing Survey of Food Intake by Individuals (CSFII), in which the assessment of the portion size was optimal. When the standard portion sizes were adjusted using the correction factor, the ability of the standard portion sizes to assess the absolute nutrient intake at the group level was considerably improved. CONCLUSIONS: This study suggests that the adjusted standard portion sizes may be able to replace missing portion sizes in the ACLS database.

Adult↗
PubMed2003

The estimation of food portion sizes: a comparison between using descriptions of portion sizes and a photographic food atlas by children and adults.

BACKGROUND: Food Photographs and standard portion sizes have been used with adults to assess portion size when recording dietary intake. The effectiveness of these methods may be reduced when memory/recall is required and children may have problems using these techniques. METHODS: Adults (47) and children (37) were recruited from amongst university personnel, their children and children's friends to assess portion sizes of nine self-served amounts of selected food items using food photographs and standard descriptions of portion sizes. Portion sizes were estimated directly after self-serving and three - 4 days later. RESULTS: Substantial differences in the estimate of portion sizes were observed for most foods regardless of the method used or the age of the subjects, median difference range: -52-100%. For children there were greater errors using both methods than for adults. Significant differences were found between the two methods of estimating weight. The food atlas provided higher median estimated weights for the majority of the food items. There were very few differences in the estimation of portion sizes between the two testing periods. CONCLUSION: The findings would suggest that either an alternative method or a modification of the methods used here for estimating portion sizes in young subjects, for example standard food portion sizes for children of different ages such as those that are being developed by the Food Standards Agency, would be more appropriate.

Adolescent↗
PubMed2004

The effect of practical portion size measurement aids on the accuracy of portion size estimates made by young adults.

A barrier to controlling the amount of food consumed may be the difficulty consumers have in accurately estimating portion sizes. Although portion size measurement aids (PSMAs) can improve estimation accuracy, their bulk and/or cost tends to make them impractical for regular use. The purpose of this study was to investigate the effect on portion size estimation accuracy of two practical PSMAs: a 2-D PSMA (life size picture of tennis and golf balls) and 3-D PSMAs (tennis and golf balls). Young adults were randomly assigned to one of two groups and estimated the portion sizes of 36 foods divided into three equal sets. PSMAs were not used to estimate portion sizes in Food Set 1. Study group 1 (n = 57) used the 2-D PSMA and study group 2 (n = 56) used the 3-D PSMAs to estimate the portion sizes in Food Set 2. Neither group used PSMAs to estimate portion sizes in Food Set 3. Repeated measures anova indicated that both groups significantly improved estimation accuracy between Food Sets 1 and 2 and between Foods Sets 1 and 3. Thus, even short-term exposure to practical PSMAs may improve estimation accuracy and these improvements persist when the PSMA is no longer available. However, the accuracy rate for Food Set 2 was only about 60% indicating that a great deal of estimation error remains.

Adolescent↗
PubMed2005

Effects on hunger and satiety, perceived portion size and pleasantness of taste of varying the portion size of foods: a brief review of selected studies.

The portion size of foods has been identified as an important environmental factor known to affect short-term energy intake. Experiments that were conducted both in the free-living environment and in laboratory-based settings to investigate the effects of portion size on energy intake unanimously showed that as the portion size of food increased, so did subjects' energy intake. Despite the fact that the profound effects of portion size on energy intake are well documented, the mechanisms by which portion size affects energy intake are poorly understood. There is some evidence that sensory influences (e.g. visual and olfactory cues), cognitive factors (e.g. learning, social norms, monetary considerations), and post-ingestive consequences (e.g. sensations of hunger and fullness) related to the portion size of foods may interact to affect the amount of food that is consumed during a meal.

Energy Intake↗
PubMed1989

The impact of training, food type, gender, and container size on the estimation of food portion sizes.

Students in a large introductory nutrition course were divided into two groups, one that received training on estimating food quantities and one that received no instruction. Training consisted of 10-minute sessions in which 76 subjects (in groups of 10) passed around and viewed food models labeled with their portion sizes while one of the investigators verbally indicated the quantities. Immediately following instruction, the trained subjects individually estimated portion sizes of one of four displays of six foods: two solids (meat loaf and fish), two liquids (milk and soup), and two amorphous items (spaghetti and apple sauce). The second group of subjects, who had received no training, also estimated the same portion sizes of the same foods in the same displays. The four displays were set up in separate rooms, with the same foods and portion sizes in each, but different container size combinations were used (smaller vs. larger containers). Both training and type of food had a significant effect; training improved estimations, and, in general, solids were better estimated than liquids, which were better estimated than amorphous items. Although results were mixed, women tended to estimate more accurately than men. There was some tendency for estimates to be more accurate when made for foods in small containers. The authors conclude that a training session enhances the accuracy of individuals estimating food quantity and that accuracy of estimates differs for different food types.

Analysis of Variance↗
PubMed2006

Portion distortion: typical portion sizes selected by young adults.

OBJECTIVE: The incidence of obesity has increased in parallel with increasing portion sizes of individually packaged and ready-to-eat prepared foods as well as foods served at restaurants. Portion distortion (perceiving large portion sizes as appropriate amounts to eat at a single eating occasion) may contribute to increasing energy intakes and expanding waistlines. The purpose of this study was to determine typical portion sizes that young adults select, how typical portion sizes compare with reference portion sizes (based in this study on the Nutrition Labeling and Education Act's quantities of food customarily eaten per eating occasion), and whether the size of typical portions has changed over time. SUBJECTS: Young adults (n=177, 75% female, age range 16 to 26 years) at a major northeastern university. METHODS: Participants served themselves typical portion sizes of eight foods at breakfast (n=63) or six foods at lunch or dinner (n=62, n=52, respectively). Typical portion-size selections were unobtrusively weighed. A unit score was calculated by awarding 1 point for each food with a typical portion size that was within 25% larger or smaller than the reference portion; larger or smaller portions were given 0 points. Thus, each participant's unit score could range from 0 to 8 at breakfast or 0 to 6 at lunch and dinner. Analysis of variance or t tests were used to determine whether typical and reference portion sizes differed, and whether typical portion sizes changed over time. RESULTS: Mean unit scores (+/-standard deviation) were 3.63+/-1.27 and 1.89+/-1.14, for breakfast and lunch/dinner, respectively, indicating little agreement between typical and reference portion sizes. Typical portions sizes in this study tended to be significantly different from those selected by young adults in a similar study conducted 2 decades ago. CONCLUSIONS: Portion distortion seems to affect the portion sizes selected by young adults for some foods. This phenomenon has the potential to hinder weight loss, weight maintenance, and/or health improvement efforts. Thus, to ensure more effective nutrition counseling, food and nutrition professionals must develop ways to "undistort" what clients perceive to be typical portion sizes and help them recognize what is an appropriate amount to eat at a single eating occasion.

Adolescent↗
PubMedDate not supplied

Patterns and trends in food portion sizes, 1977-1998.

CONTEXT: While general consensus holds that food portion sizes are increasing, no empirical data have documented actual increases. OBJECTIVE: To determine trends in food portion sizes consumed in the United States, by eating location and food source. DESIGN, SETTING, AND PARTICIPANTS: Nationally representative data from the Nationwide Food Consumption Survey (1977-1978) and the Continuing Survey of Food Intake by Individuals (1989-1991, 1994-1996, and 1998). The sample consists of 63 380 individuals aged 2 years and older. MAIN OUTCOME MEASURE: For each survey year, average portion size consumed from specific food items (salty snacks, desserts, soft drinks, fruit drinks, french fries, hamburgers, cheeseburgers, pizza, and Mexican food) by eating location (home, restaurant, or fast food). RESULTS: Portion sizes vary by food source, with the largest portions consumed at fast food establishments and the smallest at other restaurants. Between 1977 and 1996, food portion sizes increased both inside and outside the home for all categories except pizza. The energy intake and portion size of salty snacks increased by 93 kcal (from 1.0 to 1.6 oz [28.4 to 45.4 g]), soft drinks by 49 kcal (13.1 to 19.9 fl oz [387.4 to 588.4 mL]), hamburgers by 97 kcal (5.7 to 7.0 oz [161.6 to 198.4 g]), french fries by 68 kcal (3.1 to 3.6 oz [87.9 to 102.1 g]), and Mexican food by 133 kcal (6.3 to 8.0 oz [178.6 to 226.8 g]). CONCLUSION: Portion sizes and energy intake for specific food types have increased markedly with greatest increases for food consumed at fast food establishments and in the home.

Data Collection↗
PubMed2005

Can children and adolescents use photographs of food to estimate portion sizes?

OBJECTIVE: The goals of this study were to investigate whether children and adolescents can accurately estimate portion sizes of preweighed food by viewing photographs of food, and whether age influences the ability to estimate food portion sizes. SUBJECTS: A total of 63 male and female volunteers aged 9-19 y participated in the study. DESIGN: Each participant received a photographic booklet with photograph series of 13 food items. Participants over 10 y of age were asked to estimate portion sizes of food on 34 plates placed in front of them by comparing the different portions to corresponding photographs of food. Younger participants were asked to estimate portion sizes of food on 17 plates by comparing the portions to photographs. RESULTS: Participants made 2019 comparisons between actual food portion sizes and photographs of food portion sizes. On average, 60% of the comparisons were made correctly. A photograph directly adjacent to the photograph depicting the correct portion size was chosen in 35% of the comparisons and 5% of the comparisons were made incorrectly. Portion sizes were estimated more accurately when the actual served portions of food had exactly the same appearance as the foods portrayed in the photographic booklet. No differences existed between children's and adolescents' abilities to estimate portion sizes using photographs. CONCLUSIONS: Large variability may exist in an individual's capability of choosing a photograph that correctly depicts food portion sizes, but the error at the group level is quite small. These data indicate that a photographic booklet of foods can be a useful tool for portion size estimates in these age groups. SPONSORSHIP: The Norwegian Foundation for Health and Rehabilitation through Norwegian Health Association.

Adolescent↗
PubMed1996

Food photography II: use of food photographs for estimating portion size and the nutrient content of meals.

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/m2, 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/m2 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.

Adult↗
PubMed1994

Food photography. I: The perception of food portion size from photographs.

Fifty-one male and female volunteers aged 18-90 years from a wide variety of social and occupational backgrounds completed 7284 assessments of portion size in relation to food photographs. Subjects were shown six portion sizes (two small, two medium and two large) for each of six foods, and asked to compare the amount on the plate in front of them to (a) a series of eight photographs showing weights of portions from the 5th to the 95th centile of portion size (British Adult Dietary Survey), or (b) a single photograph of the average (median) portion size. Photographs were prepared either in colour or in black and white, and in two different sizes. The order of presentation of foods; use of black and white or colour; the size of photographs; and presentation of eight or average photographs were each randomized independently. On average, the mean differences between the portion size presented and the estimate of portion size using the photographs varied from -8 to +6 g (-4 to +5%) for the series of eight photographs, and from -34 to -1 g (-23 to +9%) for the single average photograph. Large portion sizes tended to be underestimated more than medium or small portion sizes, especially when using the average photograph (from -79 to -14 g, -37 to -13%). Being female, 65 years and over, or retired, or seeing photographs in colour, were all associated with small but statistically significant overestimations of portion size. Having a body mass index > or = 30 kg/m2 was associated with an 8% underestimate of portion size. We conclude that use of a series of eight photographs is associated with relatively small errors in portion size perception, whereas use of an average photograph is consistently associated with substantial underestimation across a variety of foods.

Adolescent↗
PubMed2003

Expanding portion sizes in the US marketplace: implications for nutrition counseling.

The greater energy content of larger food portions could be contributing to the increasing prevalence of overweight. Prevention guidelines recommend "sensible" portion sizes but do not define them. The US Department of Agriculture (USDA) defines standard serving sizes for dietary guidance, and the Food and Drug Administration (FDA) defines standard servings for food labels. To use these standards in counseling, nutritionists must know the sizes of portions available in the marketplace. We determined marketplace portion sizes, identified changes in these sizes with time, and compared current marketplace portions with federal standards. Most marketplace portions exceed standard serving sizes by at least a factor of 2 and sometimes 8-fold. Portions have increased over time; those offered by fast-food chains, for example, often are 2 to 5 times larger than the original size. The discrepancy between marketplace portions and standard servings suggests the need for greater emphasis on the relationship of portion size to energy intake as a factor in weight maintenance.

Counseling↗
PubMed1991

Comparison of a food frequency questionnaire using reported vs standard portion sizes for classifying individuals according to nutrient intake.

Individual intakes of retinol, carotene, vitamin C, and folacin calculated from a food frequency questionnaire using reported portion size were compared with intakes calculated using standard portion size information. Data from a case-control study to determine the association of nutrient intake and risk of cervical dysplasia were supplemented by standard portion size information from the US Department of Agriculture and reanalyzed. Significant mean differences were found between intake calculated from reported portion size data and that calculated from standard portion size data for all nutrients. Correlation of nutrient intakes obtained by the two methods of data collection ranged from .73 to .92. Calculation of the rho statistic, measuring the consistency of classification of participants into groups of high, medium, and low nutrient intake, led to values ranging from .55 to .71, indicating some misclassification of study participants. To determine the effect misclassification had on the study outcome, odds ratios were calculated using nutrient amounts obtained from both methods of collecting portion size data. Results indicate that replacing reported portion size data with standard portion size data may lead to conflicting outcomes for specific nutrients in research concerning the relationship between diet and disease.

Adult↗
PubMed2003

Comparison of digital photography to weighed and visual estimation of portion sizes.

OBJECTIVE: The primary goal was to test the validity of digital photography for measuring food portion sizes compared with weighed foods and with direct visual estimation. SAMPLES: A total of 60 test meals consisting of 10 different portion sizes from six different university cafeteria menus were prepared and weighed. DESIGN: Food selections and plate waste, as estimated by digital photography and direct visual estimation, were compared with weighed foods. For each method, three observers independently estimated portion sizes of each food. Observers expressed the portion sizes as a percentage of a standard serving. These percentages were multiplied by the weight of the standard portion to yield estimated weights. Statistical analyses To test validity, the estimates of food weights derived from both methods were compared with weighed foods using correlations and were compared with each other using Bland-Altman regression analysis. RESULTS: For the digital photography and direct visual estimation methods, estimates of the portion sizes for food selections, plate waste, and food intake were highly correlated with weighed foods. Both methods tended to yield small overestimates or underestimates. Bland-Altman regression found the two estimation methods to yield comparable results (bias less than 1.5 g). APPLICATIONS/CONCLUSIONS: These findings support the validity of the digital photography method for measuring portion sizes. Digital photography may be most useful for measuring food intake in settings that allow for the direct observation of food selections and plate waste but require minimum disruption of the eating environment, and allow unhurried estimates of portion sizes.

Diet Records↗
PubMed2006

Relationship between portion size and energy intake among infants and toddlers: evidence of self-regulation.

OBJECTIVES: To assess whether dietary intakes of infants and young toddlers show evidence of energy self-regulation. DESIGN: Data from 24-hour recalls collected in the 2002 Feeding Infants and Toddlers Study were analyzed. Multivariate regressions were used to explore the relationship between portion size and usual energy intake as well as the relationship between portion size, number of eating occasions, number of unique foods, and energy density. SUBJECTS/SETTING: A national random sample of 3,022 US infants and toddlers 4 to 24 months of age. STATISTICAL ANALYSES PERFORMED: To measure variability in portion size, an average portion size z score was computed for each child in the sample, across 45 different food groups. The number of eating occasions was defined as the total number of times a child had anything to eat or drink during the day, excluding eating occasions that included only water and/or supplements. The total number of unique foods in a day was defined as the number of unique food codes included in the 24-hour recall, and energy density was computed as kilocalories/gram, including all foods, beverages, and water. Linear regression models were used to assess the effect of portion size and other self-regulation mechanisms on energy intake and to assess the effect of these self-regulation mechanisms on portion size. Separate analyses were performed for three age groups: 4 to 5 months, 6 to 11 months, and 12 to 24 months. RESULTS: A significant negative association was found for all age groups between the number of eating occasions and average portion size z scores, indicating that children who eat less often during the day consume larger-than-average-portion sizes and children who eat more often during the day consume smaller-than-average portions. For infants (11 months and younger), a significant negative association was noted between energy density and average portion size z scores, indicating that, as the energy density of the diet goes down, infants consume larger-than-average portions and, as the energy density of the diet goes up, they consume smaller-than-average portions. Among infants 6 to 11 months, there was a significant positive relationship between portion size and the number of unique foods consumed. For toddlers, there was no association between average portion size z scores and energy density, suggesting that energy self-regulation mechanisms are diminished in this age group. CONCLUSIONS: Our findings confirm the presence of energy self-regulation among infants and young toddlers. These findings can be used to assure parents and caregivers that infants have an innate ability to regulate energy intake. At the same time, it is important to educate parents and caregivers about the potential for environmental cues to diminish natural hunger-driven eating behaviors, even among young toddlers. Dietetics professionals should emphasize the potential adverse effects that coercive feeding behaviors can have on children's innate ability to regulate energy intake. This includes not only admonitions to "clean your plate," but overrestriction of intake that may be motivated by concerns that children are overeating.

Appetite Regulation↗
PubMed2004

Combined effects of energy density and portion size on energy intake in women.

BACKGROUND: Increases in both the portion size and energy density of food have both been shown to increase energy intake, but the combined effects of such increases have not been investigated. OBJECTIVE: The objective was to determine the combined effects of energy density and portion size on energy intake in women. DESIGN: This study used a within-subjects design. Once a week for 6 wk, 39 women were served breakfast, lunch, and dinner ad libitum. The main entrée at lunch was formulated in 2 versions that varied in energy density (5.23 or 7.32 kJ/g), each of which was served in 3 different portion sizes (500, 700, or 900 g). The 2 versions were matched for macronutrient composition and palatability. Breakfast and dinner were standard meals. RESULTS: Increases in portion size and energy density led to independent and additive increases in energy intake (P <0.0001). Subjects consumed 56% more energy (925 kJ) when served the largest portion of the higher energy-dense entrée than when served the smallest portion of the lower energy-dense entrée. Subjects did not compensate for the additional intake by eating less at the subsequent meal. Despite substantial differences in energy intake, no systematic differences in ratings of hunger and fullness across conditions were observed. CONCLUSIONS: The energy density and the portion size of a food act independently to affect energy intake. The findings indicate that large portions of foods with a high energy density may facilitate the overconsumption of energy.

Adult↗
PubMed1994

Validity of individual portion size estimates in a food frequency questionnaire.

BACKGROUND: Dietary surveys often rely upon subjects' ability to estimate their portion sizes instead of weighing them, but information on the validity of such estimates is lacking. This study investigated the validity of estimated portion sizes from a self-administered food frequency questionnaire including photos. METHODS: Validity was evaluated by comparison with portion sizes from 14-day weighed food records. Eight sets of photos were included in the study (three meat dishes, one fish dish, three vegetables, potatoes), each set with four options. Subjects (59 men, 85 women) were 40-64 years. RESULTS: The majority of subjects (85-95%) selected the most correct photo or a neighbouring photo. However, regression analyses showed that the relationship between the estimated and the measured portion sizes was relatively weak for most of the foods tested, and correlations were only significant for three of the eight foods. This apparent contradiction was partly due to the pattern of the error: subjects selecting small portions had underestimated their actual portions while subjects selecting large portions had overestimated them. This error pattern could not be explained by the theoretical error resulting from the use of four discrete portion sizes instead of continuous weights, neither was it a simple consequence of the unidirectional errors at the extreme ends. Actual portion sizes varied from day to day, with intra-individual coefficients of variation of 34-40%. CONCLUSIONS: The photos used in the present study were of limited value for ranking individuals correctly according to their actual portion sizes. Whether this is a common feature of photos used in food frequency questionnaires remains to be answered.

Adult↗
PubMed2002

Portion size of food affects energy intake in normal-weight and overweight men and women.

BACKGROUND: Large portions of food may contribute to excess energy intake and greater obesity. However, data on the effects of portion size on food intake in adults are limited. OBJECTIVES: We examined the effect of portion size on intake during a single meal. We also investigated whether the response to portion size depended on which person, the subject or the experimenter, determined the amount of food on the plate. DESIGN: Fifty-one men and women were served lunch 1 d/wk for 4 wk. Lunch included an entrée of macaroni and cheese consumed ad libitum. At each meal, subjects were presented with 1 of 4 portions of the entrée: 500, 625, 750, or 1000 g. One group of subjects received the portion on a plate, and a second group received it in a serving dish and took the amount they desired on their plates. RESULTS: Portion size significantly influenced energy intake at lunch (P < 0.0001). Subjects consumed 30% more energy (676 kJ) when offered the largest portion than when offered the smallest portion. The response to the variations in portion size was not influenced by who determined the amount of food on the plate or by subject characteristics such as sex, body mass index, or scores for dietary restraint or disinhibition. CONCLUSIONS: Larger portions led to greater energy intake regardless of serving method and subject characteristics. Portion size is a modifiable determinant of energy intake that should be addressed in connection with the prevention and treatment of obesity.

Adult↗
PubMed2006

Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake.

BACKGROUND: When the portion size and energy density (in kcal/g) of a food are varied simultaneously in a single meal, each influences energy intake independently. OBJECTIVE: We aimed to determine how the effects of portion size and energy density combine to influence energy intake and satiety over multiple meals for 2 d. DESIGN: In a crossover design, 24 young women were provided with meals and snacks for 2 consecutive days per week for 4 wk; all foods were consumed ad libitum. Across the 4 sessions, the subjects were served the same 2 daily menus, but all foods were varied in portion size and energy density between a standard level (100%) and a reduced level (75%). RESULTS: Reducing the portion size and energy density of all foods led to significant and independent decreases in energy intake over 2 d (P < 0.0001). A 25% decrease in portion size led to a 10% decrease in energy intake (231 kcal/d), and a 25% decrease in energy density led to a 24% decrease in energy intake (575 kcal/d). The effects on energy intake were additive and were sustained from meal to meal. Despite the large variation in energy intake, there were no significant differences in the ratings of hunger and fullness across conditions over the 2 d. CONCLUSIONS: Reductions in portion size and energy density independently decreased ad libitum energy intake in women when commonly consumed foods were served over 2 d. Reductions in both portion size and energy density can help to moderate energy intake without increased hunger.

Adult↗