Beverage consumption, appetite, and energy intake: what did you expect?

Episodic memory and appetite regulation in humans

Psychological and neurobiological evidence implicates hippocampal-dependent memory processes in the control of hunger and food intake. In humans, these have been revealed in the hyperphagia that is associated with amnesia. However, it remains unclear whether ‘memory for recent eating’ plays a significant role in neurologically intact humans. In this study we isolated the extent to which memory for a recently consumed meal influences hunger and fullness over a three-hour period. Before lunch, half of our volunteers were shown 300 ml of soup and half were shown 500 ml. Orthogonal to this, half consumed 300 ml and half consumed 500 ml. This process yielded four separate groups (25 volunteers in each). Independent manipulation of the ‘actual’ and ‘perceived’ soup portion was achieved using a computer-controlled peristaltic pump. This was designed to either refill or draw soup from a soup bowl in a covert manner. Immediately after lunch, self-reported hunger was influenced by the actual and not the perceived amount of soup consumed. However, two and three hours after meal termination this pattern was reversed - hunger was predicted by the perceived amount and not the actual amount. Participants who thought they had consumed the larger 500-ml portion reported significantly less hunger. This was also associated with an increase in the ‘expected satiation’ of the soup 24-hours later. For the first time, this manipulation exposes the independent and important contribution of memory processes to satiety. Opportunities exist to capitalise on this finding to reduce energy intake in humans.

Association of food form with self-reported 24-h energy intake and meal patterns in US adults: NHANES 2003-2008

BACKGROUND

Laboratory studies suggest that food form (beverages compared with solid foods) evokes behavioral and physiologic responses that modify short-term appetite and food intake. Beverage energy may be less satiating and poorly compensated, which leads to higher energy intake.

OBJECTIVE

We examined associations between 24-h energy consumed in beverages and a variety of meal and dietary attributes to quantify the contribution of beverage consumption to the energy content of diets in free-living individuals consuming their self-selected diets.

DESIGN

We used dietary recall data for adults (n = 13,704) in NHANES 2003-2008 to examine the multiple covariate-adjusted associations between 24-h energy from beverages and nonbeverages and associations between beverage intake, eating behaviors, and the energy density of beverage and nonbeverage foods.

RESULTS

In the highest tertile of 24-h beverage energy intake, beverages provided >30% of energy. Total 24-h energy and nonbeverage energy consumption and energy density (kcal/g) of both beverage and nonbeverage foods increased with increasing energy from beverages (P < 0.0001). With increasing 24-h beverage energy consumption, the reported frequency of all, snack, and beverage-only ingestive episodes and length of the ingestive period increased, whereas the percentage of energy from main meals decreased (P < 0.0001).

CONCLUSIONS

Higher 24-h beverage energy intake was related to higher energy intake from nonbeverage foods, quality of food selections, and distribution of 24-h energy into main meal and snack episodes. Moderation of beverage-only ingestive episodes and curtailing the length of the ingestion period may hold potential to lower uncompensated beverage energy consumption in the US population.

Soups increase satiety through delayed gastric emptying yet increased glycaemic response

BACKGROUND/OBJECTIVES

Previous studies have demonstrated the satiating properties of soups compared with solids; however, the mechanisms controlling soup-induced satiety are unknown. This study aimed to understand the physiological mechanisms causing soup to be more satiating.

SUBJECTS/METHODS

A total of 12 volunteers were tested on three occasions after a solid meal, chunky soup or smooth soup test meal for gastric emptying (GE) using the sodium [1-¹³C] acetate breath test, satiety using visual analog scales (VAS) and glycaemic response (GR) using finger prick blood samples.

RESULTS

There was a significant difference in GE half-time (P=0.022) and GE ascension time (P=0.018), with the longest GE times for the smooth soup and the shortest for the solid meal. The GR area under the curve was significantly different between meals (P=0.040). The smooth soup had the greatest GR (87.0 ± 49.5 mmol/l/min), followed by the chunky soup (65.4 ± 48.0 mmol/l/min), with the solid meal having the lowest GR (61.6 ± 36.8 mmol/l/min). Volunteers were fuller after the smooth soup compared with solid meal (P=0.034).

CONCLUSIONS

The smooth soup induced greater fullness compared with the solid meal because of a combination of delayed GE leading to feelings of gastric distension and rapid accessibility of nutrients causing a greater glycaemic response.

A trial of sugar-free or sugar-sweetened beverages and body weight in children

BACKGROUND

The consumption of beverages that contain sugar is associated with overweight, possibly because liquid sugars do not lead to a sense of satiety, so the consumption of other foods is not reduced. However, data are lacking to show that the replacement of sugar-containing beverages with noncaloric beverages diminishes weight gain.

METHODS

We conducted an 18-month trial involving 641 primarily normal-weight children from 4 years 10 months to 11 years 11 months of age. Participants were randomly assigned to receive 250 ml (8 oz) per day of a sugar-free, artificially sweetened beverage (sugar-free group) or a similar sugar-containing beverage that provided 104 kcal (sugar group). Beverages were distributed through schools. At 18 months, 26% of the children had stopped consuming the beverages; the data from children who did not complete the study were imputed.

RESULTS

The z score for the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) increased on average by 0.02 SD units in the sugar-free group and by 0.15 SD units in the sugar group; the 95% confidence interval (CI) of the difference was -0.21 to -0.05. Weight increased by 6.35 kg in the sugar-free group as compared with 7.37 kg in the sugar group (95% CI for the difference, -1.54 to -0.48). The skinfold-thickness measurements, waist-to-height ratio, and fat mass also increased significantly less in the sugar-free group. Adverse events were minor. When we combined measurements at 18 months in 136 children who had discontinued the study with those in 477 children who completed the study, the BMI z score increased by 0.06 SD units in the sugar-free group and by 0.12 SD units in the sugar group (P=0.06).

CONCLUSIONS

Masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children. (Funded by the Netherlands Organization for Health Research and Development and others; DRINK ClinicalTrials.gov number, NCT00893529.).