Participants were requested to complete an entry in the diary as soon as possible after having consumed the extra food, and the diary was returned each morning. A daily total of out of study energy intake was calculated from participant diaries using myfood24 [ 19 , 20 ].

Fitbit device estimates of MVPA have been validated against gold standard research-grade physical activity monitoring devices, and data from the devices have good reliability [ 21 , 22 , 23 ]. Although the validity of the IPAQ against objective measures of physical activity is limited, the measure has acceptable reliability making it suitable for assessing within-person changes in activity in crossover designs [ 24 , 25 ].

Daily hunger and fullness ratings across time were summarised by calculating the area under the curve using the trapezoid function [ 26 ]. Height was measured during the screening session using a stadiometer Seca to the nearest 0.

Measurements were taken without shoes and heavy outer clothing. Perceived normality of each portion size was assessed at the end of the study in a computerised task programmed in Psychopy [ 27 ].

At the end of the study participants were asked to report what they thought were the aims of the study. See Additional file 1 for full details. All statistical analyses were conducted in IBM SPSS The primary dependent measures were a daily energy intake sum of energy intake from all laboratory meals, snack box, and self-reported additional energy intake b immediate additional intake energy intake from self-served additional helpings of lunch, self-served dessert at dinner , c total main meal intake sum of energy intake from main component and additional intake at lunch, dinner.

In our primary pre-registered analyses alpha was set at 0. As decided a priori , data from these participants are included in the reported analyses, and the significance of primary results did not vary depending on their inclusion unless otherwise stated.

We also examined whether the pattern of results was dependent on the order in which portion size conditions were presented see Additional file 1. We conducted a series of analyses to assess the impact of portion size manipulation on secondary outcome measures hunger and fullness, objective MVPA, self-reported discretionary LTPA.

Exploratory analyses examined the effect of portion size condition on breakfast, snack box, and out of study energy intake. Thirty-nine participants were enrolled in the study after completing online and in-person eligibility screening.

See Table 1 for sample characteristics and Fig. Portion size condition had a significant effect on daily energy intake and there was no significant interaction between portion size condition and day see Table 2 for means, Table 3 for ANOVA results, and Additional file 1 for energy intake plotted by day.

Effect of portion size on daily energy intake. There was a significant effect of portion size condition on immediate additional intake at lunch and dinner combined , and a significant interaction between condition and meal see Table 3 for ANOVA results. In separate portion size condition x day repeated-measures ANOVAs for lunch and dinner, portion size condition significantly affected immediate additional intake, with no significant interaction between portion size and day.

Effect of portion size on immediate additional intake of other meal food at lunch left and dessert food at dinner right. There was a significant effect of portion size on total main meal intake lunch and dinner combined , and a significant interaction between portion size condition and meal see Table 3 for ANOVA results.

In separate portion size condition x day repeated-measures ANOVAs for lunch and dinner, portion size condition significantly affected total meal intake, with no significant interaction between portion size condition and day.

Effect of portion size on total meal intake sum of intake from initial portion and additional intake of other meal food at lunch left , and sum of intake from initial portion and additional intake of dessert food at dinner right.

We examined the pattern of results across groups according to the sequence in which participants received the portion size conditions and found little evidence that condition sequence affected the results of the main analyses. There was a significant interaction between condition sequence and portion size condition for total lunch meal energy intake.

However, controlling for condition sequence did not alter the significance of pairwise comparisons between portion size conditions and the pattern of results was largely consistent across condition sequences see Additional file 1.

There were no significant effects of portion size condition on hunger or fullness, daily moderate to vigorous physical activity, discretionary leisure-time physical activity, or body weight see Table 2 for descriptive statistics, and Additional file 1 : Table S2 for full ANOVA results.

In exploratory analyses, neither breakfast, snack box, nor out of study self-reported energy intake significantly varied between portion size conditions Table 2 ; Additional file 1 : Table S2.

The study was not designed or powered to detect moderation by individual differences, but the pattern of daily energy intake across conditions was consistent across gender and BMI groups see Additional file 1 : Figure S4. Rather, the results of the present study suggest that reductions to the portion size of main-meal foods result in significant decreases in daily energy intake regardless of the perceived normality of portion size.

Even reductions to portion size that are noticeable and result in portions that appear small lowered daily energy intake. The results of the present study are not fully consistent with some of the results from two acute single meal studies [ 9 ].

However, in the previous studies [ 9 ], each reduction to the portion size of the main meal component resulted in a significant reduction in total meal intake at both lunch and dinner. Additional eating only partially made up for the difference in intake from the initial portion.

This was also observed in the present study. Therefore, unlike findings from virtual and short-term food intake studies [ 9 , 15 ], results of the present study are not consistent with a norm range model of portion size, as reducing portions past the point of perceived normality did not significantly alter via additional eating the influence portion size had on daily energy intake.

It may be the case that when food intake is examined over longer periods of time, cognitive appraisals like perceived normality of portion size may have a smaller influence on additional eating behaviour than in the short-term [ 9 ].

A sizable proportion of the reduction to portion size at main meals was transferred to overall energy intake. These findings are consistent with the results of a systematic review which demonstrated that energy deficits imposed by experimental manipulation are poorly compensated for [ 30 ].

A potential argument against reducing portions of commercially available food products is that consumers may compensate through additional eating for the reduced portions which may result in no overall benefit to total energy intake [ 31 ]. This approach was adopted to minimise hypothesis awareness among the study participants that would likely have been compromised by completing pre-study ratings of portion size normality.

These slight differences may be attributable to the manipulation check methodology. Manipulation check data may have been contaminated by repeated exposure to and consumption of the dishes during the study [ 32 , 33 ]. The manipulation checks for each portion size were also administered consecutively and this may have artificially produced larger differences between the portion size conditions.

Although we requested that participants not consume food outside of the study, we accounted for any energy intake consumed outside of the laboratory using self-reported food diaries. This self-reported intake may be subject to some underreporting, but we presume this would be similar across conditions.

A limitation is that most participants in the present study had at least some university education. A different pattern of results may have been observed with a more representative sample, as evidence from an online study suggests that portion size influences intended food consumption to a greater extent among individuals with lower education [ 34 ].

Energy intake was examined in response to three manipulated portion sizes. Examination of energy intake from a wider range of portion sizes will be useful to identify the point at which reduced portions trigger significant compensatory behaviour and to enable testing of other potential mechanisms that could determine this point.

We examined energy intake over five days as this is feasible in a laboratory setting. All study foods were standardised across testing periods and were neutral to moderately liked by participants, meaning that additional intake is unlikely to have been unduly affected by dislike of study foods.

However, as is the case with any laboratory-based experiment, responses to manipulations of portion size may differ in free-living settings. The artificial environment imposed in controlled laboratory-based experiments including but not limited to the provision of a limited number of free foods may impact on energy intake and the extent to which compensation for reduced portion sizes occurs.

Replication in real-world settings would now be informative. Reductions to the portion size of main-meal foods resulted in significant decreases to daily energy intake, even when portions were reduced to the point that they were no longer perceived as being normal in size.

Even relatively large reductions to portion size that are noticeable and result in portions that appear small are still likely to lower total energy intake. Hollands GJ, Shemilt I, Marteau TM, Jebb SA, Lewis HB, Wei Y, Higgins, JPT, Ogilvie D. Portion, package or tableware size for changing selection and consumption of food, alcohol and tobacco.

Cochrane Database Syst Rev. Zlatevska N, Dubelaar C, Holden SS. Sizing up the effect of portion size on consumption: a meta-analytic review. J Mark. Article Google Scholar. Levitsky DA. The non-regulation of food intake in humans: Hope for reversing the epidemic of obesity.

Physiol Behav. Article CAS Google Scholar. Livingstone MBE, Pourshahidi LK. Portion size and obesity. Adv Nutr: Int Rev J. Marteau TM, Hollands GJ, Shemilt I, Jebb SA. Downsizing: policy options to reduce portion sizes to help tackle obesity.

Br Med J. Nielsen SJ, Popkin BM. Patterns and trends in food portion sizes, J Am Med Assoc. Steenhuis I, Poelman M. Portion size: latest developments and interventions. Curr Obes Rep. Lewis HB, Ahern AL, Solis-Trapala I, Walker CG, Reimann F, Gribble FM, et al.

Effect of reducing portion size at a compulsory meal on later energy intake, gut hormones, and appetite in overweight adults. Haynes A, Hardman CA, Halford JCG, Jebb SA, Robinson E. Portion size normality and additional within-meal food intake: two crossover laboratory experiments.

Br J Nutr. Rolls BJ, Roe LS, Meengs JS. Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake.

Am J Clin Nutr. Vermote M, Versele V, Stok M, Mullie P, D'Hondt E, Deforche B, et al. The effect of a portion size intervention on French fries consumption, plate waste, satiety and compensatory caloric intake: an on-campus restaurant experiment.

Nutr J. Reale S, Kearney C, Hetherington M, Croden F, Cecil J, Carstairs S, et al. The feasibility and acceptability of two methods of snack portion control in United Kingdom UK preschool children: reduction and replacement.

Google Scholar. Carstairs S, Caton S, Blundell-Birtill P, Rolls B, Hetherington M, Cecil J. Can reduced intake associated with downsizing a high energy dense meal item be offset by increased vegetable variety in 3—5-year-old children?

French SA, Mitchell NR, Wolfson J, Harnack LJ, Jeffery RW, Gerlach AF, et al. Portion size effects on weight gain in a free living setting. Haynes A, Hardman CA, Makin ADJ, Halford JCG, Jebb SA, Robinson E.

Visual perceptions of portion size normality and intended food consumption: a norm range model. Food Qual Prefer. Halford JCG, Masic U, Marsaux CFM, Jones AJ, Lluch A, Marciani L, et al.

Download in PDF KB. The Nutrition Facts label on packaged foods and drinks makes it easier for you to make informed choices. Serving Size Calories Percent Daily Value Added Sugars. First, look at the serving size and the number of servings per container, which are at the top of the label.

The serving size is shown as a common household measure that is appropriate to the food such as cup, tablespoon, piece, slice, or jar , followed by the metric amount in grams g. The nutrition information listed on the Nutrition Facts label is usually based on one serving of the food; however, some containers may also have information displayed per package.

By law, serving sizes must be based on the amount of food people typically consume, rather than how much they should consume. Serving sizes reflect the amount people typically eat and drink.

Do you understand the difference between a portion and a serving? The information below explains portions and servings, and it provides tips to help you eat just enough for you.

A portion is how much food you choose to eat at one time, whether in a restaurant, from a package, or at home. Different products have different serving sizes. Sizes can be measured in cups, ounces, grams, pieces, slices, or numbers—such as three crackers. Depending on how much you choose to eat, your portion size may or may not match the serving size.

To see how many servings a container has, look at the top of the label. But the container has four servings. Do a little math to find out how many calories you would really be getting.

In this case, eating two servings would mean getting twice the calories—and other nutrients—that are listed on the food label. The U. Food and Drug Administration FDA changed some food and beverage serving sizes so the labels more closely match how much we typically eat and drink.

As a result of recent updates to the Nutrition Facts label , some serving sizes on food labels may be larger or smaller than they were before see Figure 2 below.

A serving size of yogurt used to be 8 ounces. Remember: The serving size on a label is not a recommendation of how much you should eat or drink. The serving size on a food label may be more than or less than the amount you should eat. To help you figure out how many calories are just enough for you, check out the following resources.

The food label tells you how many calories and how much fat , protein , carbohydrates , and other nutrients are in one food serving. Many packaged foods contain more than a single serving. The updated food label lists the number of calories in one serving size using larger print than before, so it is easier to read.

One way to become healthier now and in the future is to use the Nutrition Facts label together with the MyPlate Plan that helps you figure out how many calories you need each day. Using the two together, as shown in Figure 4 below, can help you figure out how many vegetables , fruits , grains , protein foods , and dairy products your body needs.

Checking food labels for calories per serving is one step toward managing your food portions. Create a food tracker on your cellphone, calendar, or computer to record the information.

Or you can download apps available for mobile devices to help you track how much you eat—and how much physical activity you get—each day. For example, the Start Simple with MyPlate app tells you how to get started and is free to download and use.

RWJ contributed to the design of the study, was the primary writer of the manuscript, and was involved in the analysis and interpretation of the data. SR coordinated the implementation of the project, recruited participants, collected and analyzed data, and wrote up the methods section of the manuscript.

CLD contributed to the conceptualization and design of the experiment and the development of measures and diet intervention components.

LJH provided assistance with study design, data collection, and data analysis. ASL contributed to the design and rationale of study. PRP provided consultation and assistance with recruitment and data collection. JEB contributed to data analysis and interpretation. All authors contributed to the manuscript writing.

Robert W Jeffery, Sarah Rydell, Caroline L Dunn, Lisa J Harnack, Allen S Levine, Paul R Pentel, Judith E Baxter and Ericka M Walsh contributed equally to this work. This article is published under license to BioMed Central Ltd. Reprints and permissions.

Jeffery, R. et al. Effects of portion size on chronic energy intake. Int J Behav Nutr Phys Act 4 , 27 Download citation. Received : 28 March Accepted : 27 June Published : 27 June Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. Search all BMC articles Search. Download PDF. Download ePub.

Abstract Background This study experimentally examined the effects of repeated exposure to different meal portion sizes on energy intake. Methods Nineteen employees of a county medical center were given free box lunches for two months, one month each of and average kcal.

Conclusion This study suggests that chronic exposure to large portion size meals can result in sustained increases in energy intake and may contribute to body weight increases over time. Background Over the last 20 to 30 years, there have been dramatic increases in the prevalence of obesity in all segments of the US population [ 1 ].

Methods Participants Participants for the present study were recruited from employees of a community medical center by posting fliers on bulletin boards, in-person recruitment outside the center cafeteria, e-mail newsletter announcements, and table tents.

Design The study employed a within-person, randomized crossover design comparing the effects of providing free box lunches of different portion sizes 5 days per week for four consecutive weeks on energy intake and body weight. Procedures This research was approved by the University of Minnesota and the Minneapolis Medical Research Foundation institutional review boards.

Measures Height and Weight: Body weight was measured on a calibrated electronic scale to the nearest 0. Analyses Statistical analyses of the data from this study were done using SAS version 8.

Results Completion rates in the study were good. Figure 1. Box Lunch Study: Effect of treatments on energy and percent fat intake at lunch and per day.

Full size image. Discussion This study showed that chronic exposure to larger portion sizes in free-living populations can induce sustained increases in energy intake and suggests that the effects of portion size may be powerful enough to affect rate of weight gain over time. Conclusion Food portion size is a readily modified characteristic of the environment.

References Flegal KM, Kuczmarski RJ, Johnson CL: Overweight and obesity in the United States: Prevalence and trends, Article CAS Google Scholar Young LR, Nestle M: The contribution of expanding portion sizes to the US obesity epidemic.

Article Google Scholar Blundell JE, Stubbs RJ, Golding C, Croden F, Alam R, Whybrow S, Le Noury J, Lawton CL: Resistance and susceptibility to weight gain: individual variability in response to a high-fat diet.

Article CAS Google Scholar Rolls BJ, Morris EL, Roe LS: Portion size of food affects energy intake in normal-weight and overweight men and women. CAS Google Scholar Diliberti N, Bordi PL, Conklin MT, Roe LS, Rolls BJ: Increased portion size leads to increased energy intake in a restaurant meal.

Article Google Scholar Levitsky DA, Youn T: The more food young adults are served, the more they overeat. CAS Google Scholar Rolls BJ, Roe LS, Kral TV, Meengs JS, Wall DE: Increasing the portion size of a packaged snack increases energy intake in men and women. Article Google Scholar Kral TV, Roe LS, Rolls BJ: Combined effects of energy density and portion size on energy intake in women.

CAS Google Scholar Wansink B, Painter JE, North J: Bottomless bowls: Why visual cues of portion size may influence intake. Article Google Scholar Rolls BJ, Roe LS, Meengs JS: Reductions in portion size and enegy density of foods are additive and lead to sustained decreases in energy intake.

CAS Google Scholar Rolls BJ, Roe LS, Meengs JS: Larger portion sizes lead to sustained increases in energy intake over 2 days. Article Google Scholar Kerver JM, Yang EJ, Obayashi S, Bianchi L, Song WO: Meal and snack patterns are associated with dietary intake of energy and nutrients in US adults.

Article Google Scholar Schakel SF: Procedures for estimating nutrient values for food composition databases. Article CAS Google Scholar Jacobs DR, Hahn LP, Haskell WL, Pirie P, Sidney S: Validity and reliability of short physical activity history: CARDIA and the Minnesota Heart Health Program.

Article Google Scholar Ainsworth BE: The Compendium of Physical Activities Tracking Guide. pdf ] Download references. Acknowledgements We thank Anna Henry, MPH nutrition student, for her help with food recalls and data entry.

View author publications. Additional information Competing interests The author s declare that they have no competing interests. Authors' contributions RWJ contributed to the design of the study, was the primary writer of the manuscript, and was involved in the analysis and interpretation of the data.

Rights and permissions This article is published under license to BioMed Central Ltd. About this article Cite this article Jeffery, R. Copy to clipboard. How do you know a reasonable portion of food when you see it? Visualize the objects mentioned below when eating out, planning a meal, or grabbing a snack.

For example, for people who eat meat, the amount recommended as part of a healthy meal is 3 to 4 ounces — it will look about the same size as a deck of cards. Even some bagels have become super-sized, which gives this reasonably healthy breakfast item a high calorie count.

Bakeries and grocery stores often carry jumbo bagels that measure 4¼ inches across and contain to calories each. A regular, 3-inch-diameter bagel has about calories. The American Cancer Society ACS recommends eating a colorful variety of fruits and vegetables each day to help prevent cancer.

Substitute low calorie, high-fiber fruits and vegetables for higher calorie foods and snacks — it will help you get the fruits and vegetables you need, feel full, and save on calories! The American Cancer Society medical and editorial content team.

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing. American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.

Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society. If this was helpful, donate to help fund patient support services, research, and cancer content updates. Skip to main content. Sign Up For Email.

Understanding Cancer What Is Cancer? Cancer Glossary Anatomy Gallery. Cancer Care Finding Care Making Treatment Decisions Treatment Side Effects Palliative Care Advanced Cancer.

Patient Navigation. End of Life Care. For Health Professionals. Cancer News. Explore All About Cancer. Connect with Survivors Breast Cancer Support Cancer Survivors Network Reach To Recovery Survivor Stories. Resource Search. Volunteer Be an Advocate Volunteer Opportunities for Organizations.

Fundraising Events Relay For Life Making Strides Against Breast Cancer Walk Endurance Events Galas, Balls, and Parties Golf Tournaments. Featured: Making Strides Against Breast Cancer. Using the two together, as shown in Figure 4 below, can help you figure out how many vegetables , fruits , grains , protein foods , and dairy products your body needs.

Checking food labels for calories per serving is one step toward managing your food portions. Create a food tracker on your cellphone, calendar, or computer to record the information.

Or you can download apps available for mobile devices to help you track how much you eat—and how much physical activity you get—each day. For example, the Start Simple with MyPlate app tells you how to get started and is free to download and use.

The sample food tracker in Figure 5 below shows what a 1-day page of a food tracker might look like. In the example, the person chose fairly healthy portions for breakfast and lunch to satisfy hunger.

The person also ate five cookies in the afternoon out of boredom rather than hunger. An early evening snack of a piece of fruit and 4 ounces of fat-free or low-fat yogurt might have prevented overeating less healthy food later.

The number of calories for the day totaled 2,—more than most people need. Taking in too many calories may lead to weight gain over time. For instance,. Using your tracker, you may become aware of when and why you consume less healthy foods and drinks.

This information may help you make different choices in the future. You may only want to do so long enough to learn typical serving and portion sizes. Try these tips to control portions at home.

Although it may be easier to manage your portions when you cook and eat at home, most people eat out from time to time—and some people eat out often. Have you noticed that it costs only a few cents more to get the large fries or soda instead of the regular or small size?

Although getting the super-sized meal for a little extra money may seem like a good deal, you end up with more calories than you need for your body to stay healthy. The NIDDK conducts and supports clinical trials in many diseases and conditions, including weight management.

The trials look to find new ways to prevent, detect, or treat disease and improve quality of life. Clinical trials—and other types of clinical studies —are part of medical research and involve people like you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Find out if clinical studies are right for you. Watch a video of NIDDK Director Dr. Griffin P.