Systematic Review and Meta-Analysis on the Effect of Portion Size and Ingestive Frequency on Energy Intake and Body Weight among Adults in Randomized Controlled Feeding Trials

Abstract

Energy intake is the product of portion size (PS)—the energy content of an ingestive event—and ingestive frequency (IF)—the number of ingestive events per unit time. An uncompensated alteration in either PS or IF would result in a change in energy intake and body weight if maintained over time. The objective of this meta-analysis was to assess the independent effects of PS and IF on energy intake and body weight among healthy adults in randomized controlled trials (RCTs). A total of 9708 articles were identified in PubMed, Web of Science, Cochrane, and CINAHL databases. The articles were divided among 10 researchers; each article was screened for eligibility by 2–3 independent reviewers. Exclusion criteria included: populations <19 y and >65 y, unhealthy populations (i.e. participants with an acute or chronic disease), assessments <24 h and <4 wk in duration for trials investigating energy intake or body weight, respectively. Controlled feeding trials (i.e. fixed energy intake) that manipulated IF and PS in the same study intervention (IF/PS) were evaluated separately and for the body weight outcome only. Twenty-two studies (IF = 4, PS = 14, IF/PS = 4) met the inclusion criteria. There was an insufficient number of studies to assess the effect of IF, PS, or IF/PS on body weight. There was heterogeneity in the effect sizes among all comparisons (I2 ≥75%). Consuming larger portion sizes was associated with higher daily energy intake [295 kcal (202, 388), n = 24; weighted mean differences (WMD) (95% CI), n = comparisons], and increased frequency of ingestive events was associated with higher energy intake [203 kcal (76, 330), n = 10]. Results from RCTs support that larger PS and greater IF are both associated with higher energy consumption. However, there is insufficient information to determine chronic effects on body weight. This protocol was registered at the International Prospective Register of Systematic Reviews (PROSPERO) as CRD42018104757.

Multisectoral Strategies Needed to Establish Healthy Portion Size Norms That Disincentivize Hyperpalatable, Energy-Dense Foods and Sugary Beverages in Food Environments Linked to Obesity and Diet-Related Chronic Diseases in the United States

“…Many factors influence or moderate the PSE and overconsumption, including premeal decisions [i.e., eating context (dining with friends or alone), price, healthfulness, convenience, and expected satiety]; environmental factors (i.e., product labeling, takeaway container availability, and size); and food, beverage, or meal features (i.e., energy and nutrient density, perceived value for cost, marketing, palatability, taste, and texture) [12,13,14]. PSE differences have been observed based on age and gender that vary by product choice, timing of eating, and leisure activities associated with overconsumption by adult and child populations [15,16].…”

“…Larger portion sizes and greater ingestive frequency of foods, beverages, or meals are associated with higher energy intake and poorer diet quality when hyperpalatable foods with high fat content, added sugars, and sodium are consumed regularly over time [4,16]. The total energy intake is the product of portion size (measured in ounces or grams), the energy content of a food or beverage product consumed (measured in kilocalories or kilojoules), and ingestive frequency over time [16].…”

Association between Meal Frequency and Type 2 Diabetes Mellitus in Rural Adults: A Large-Scale Cross-Sectional Study

“…However, it seems very difficult to maintain a constant total energy intake in free-living populations who self-reported diets, and even a higher frequency of eating could lead to a higher calorie intake. This was because frequent eating might increase the stimulation of food and result in more energy intake, thus making it difficult to control energy balance [ 29 , 30 , 31 , 32 ]. Furthermore, there was also a study pointing out that changing eating frequency had virtually no effect on glucose regulation parameters, but consumption of most calories in the evening of the day might be harmful to glycemic control [ 33 ].…”

Front-of-pack (FOP) labelling systems, nutrition education, and obesity prevention: nutri-score and nutrinform battery need more research

“…Food label regulations are based on serving size in the US and UK. Several reports, including a 2020 JAMA study, provided evidence of a marked trend towards larger portion sizes in recent decades [6,7]. Though not conclusively demonstrated with long-term studies, the relevance of reducing serving sizes to prevent obesity is consistently supported by meta-analyses correlating higher portion sizes with increased energy intake and body weight in populations [7].…”

“…Several reports, including a 2020 JAMA study, provided evidence of a marked trend towards larger portion sizes in recent decades [6,7]. Though not conclusively demonstrated with long-term studies, the relevance of reducing serving sizes to prevent obesity is consistently supported by meta-analyses correlating higher portion sizes with increased energy intake and body weight in populations [7]. Despite the complexity of defining a portion, food label systems based on the 100 g standard as reference amounts, without any reference to portion size, have raised criticisms since they tend to penalise energy-dense foods consumed in small quantities while giving favourable scores to sweetened beverages devoid of nutritional content [8].…”