Satiety: have we neglected dietary non-nutrients?

Independent effects of volume and energy density manipulation on energy intake and appetite in healthy adults: A randomized, controlled, crossover study

Consuming enough energy to meet high energy demands can be challenging for military personnel wherein logistical constraints limit food availability. Increasing dietary energy density (ED) and/or volume density (VD) of rations may be countermeasures, but whether positive linear associations between ED and energy intake (EI) hold at moderate-to-high ED and VD is unclear. This study examined the effects of covertly increasing the ED and VD of moderate ED (≥1.6 kcal/g) foods on appetite and energy intake. Twenty healthy men completed four 2-day treatments in random order by consuming a standardized diet containing three experimental food items (EXP) engineered using leavening, physical compression and fat manipulation to be isovolumetric but lower (L) or higher (H) in ED and VD creating four treatments: LED/LVD, LED/HVD, HED/LVD, HED/HVD. Consumption of EXP was compulsory during two meals and a snack, but remaining intake was self-selected (SSF). Results failed to show any ED-by-VD interactions. During LVD, EI was lower for EXP (-417 kcal [95%CI: 432, -402], p < 0.01) and TOTAL (SSF + EXP) (-276 kcal [95%CI: 470, -83], p = 0.01) compared to HVD, while SSF EI did not differ (140 kcal [-51, 332], p = 0.15). During LED, EI for EXP (-291 kcal [95%CI: 306, -276], p < 0.01) was lower than HED, while SSF EI was higher than HED (203 kcal 95%CI: [12, 394], p = 0.04) and TOTAL EI did not differ (-88 kcal [-282, 105], p = 0.36). Thus, when a small isovolumetric portion of the diet was manipulated, increasing the VD of moderate ED foods failed to elicit compensatory reductions in ad libitum EI while increasing the ED of moderate ED foods did. Findings may support VD manipulation of moderate ED foods as a strategy to promote increased short-term EI in environments wherein logistical burden may limit food volume.

The Kids Obesity Prevention Program: Cluster Randomized Controlled Trial to Evaluate a Serious Game for the Prevention and Treatment of Childhood Obesity

Background

Health games provide opportunities for the treatment and prevention of childhood obesity. We developed a motion-controlled serious game for children that addresses 3 core topics of nutrition, physical activity, and stress coping. It is the first serious game that extensively targets the dietary energy density principle (DED-P) in relation to nutrition. The game is intended to provide an additional educational component for the prevention and treatment of obesity in children.

Objective

The Kids Obesity Prevention study aimed to evaluate the newly developed game and to evaluate how well children are able to understand and apply the DED-P.

Methods

This cluster randomized controlled trial collected data from 82 primary school children aged 9 to 12 years and their parents at baseline (T0), at 2 weeks after study commencement (T1), and at the 4-week follow-up (T2). The dropout rate was 3.6%. The intervention group (IG) played the game within 2 weeks (2 sessions with different game modules). One part of the game involves selection of food with the lower energy density when presented with a pair of foods. This allows assessment of whether the children have understood the DED-P and whether they can apply it to unknown foods under time pressure. The control group (CG) received a brochure about the food pyramid concept and physical activity. The primary outcome was the gain in knowledge (nutrition and stress coping) and measured with a pretested questionnaire. The secondary outcomes were the maintenance of knowledge, application of the DED-P, feelings during game play, game acceptance, and behavioral measures (physical activity, media consumption, and dietary intake).

Results

The knowledge score ranging from 0 to 100 increased from T0 (IG: 53 [SD 10], CG: 50 [SD 11]) to T1 (IG: 69 [SD 11], CG: 52 [SD 12]) in IG versus CG (P<.001). At T2, the knowledge score of IG remained at the same level as that of T1. Game data showed that after DED-P education, the classification under time pressure of unknown versus known food pairs according to their DED category was similar (hit rate around 70%). Overall, 95% of the children liked the game very much or much. No group changes were observed at the behavioral level.

Conclusions

The Kids Obesity Prevention program sustainably increased knowledge in the areas of nutrition and stress coping, and children were able to apply the DED-P.

Trial Registration

ClinicalTrials.gov NCT02551978; https://clinicaltrials.gov/ct2/show/NCT02551978

No influence of carbonation on glycemic response, gastric emptying, and satiety of sweetened drinks

OBJECTIVE

The aim of this study was to examine the effect of carbonation of sweetened beverages on glycemic response, gastric emptying, and satiety.

METHODS

After an overnight fast, 15 healthy individuals (6 women, 9 men) consumed a 500 mL beverage containing 50 g glucose that was noncarbonated (NC), low carbonated (LC), or high carbonated (HC) at a standardized rate of consumption (100 mL/min). Blood glucose was measured at baseline and at 15, 30, 45, 60, 90, and 120 min after beverage consumption. Antral cross-sectional area was measured using ultrasound at baseline, 5, 10, 20, 30, 40, 50, 60, 90, and 120 min; for the estimation of gastric volume and gastric emptying rate. Satiety was assessed using electronic visual analog scales at the same time points as the blood glucose measurement.

RESULTS

There were no significant differences in glycemic response among the test beverages. Higher carbonation levels significantly increased antral cross-sectional area during the first 20 min after beverage consumption (P < 0.010) but did not translate into significant differences in gastric volume or gastric emptying rates. There was no significant effect of carbonation on satiety, but the area under the curve for thirst was significantly lower for HC compared with NC (P = 0.009).

CONCLUSIONS

The carbonation of a simple glucose solution did not increase glycemic response nor alter gastric emptying and subjective feelings of satiety (with the exception of thirst). The present study suggests that carbonation does not alter glycemic response.

Sustained hunger suppression from stable liquid food foams

OBJECTIVE

Simple aeration of food matrices with gas has previously been shown to generate immediate suppression of appetite, though duration of effects has not been shown. This research tested whether liquids aerated with nitrous oxide (N2 O) to achieve high in-body stability could produce enhanced and sustained effects on eating motivations.

METHODS

In two randomized cross-over studies, appetite ratings were collected for 240 min. In Study 1, 24 volunteers consumed a full portion liquid (325 ml, 190 kcal) or aerated (1,000 ml, 190 kcal) drink at 0 min, or half portions of liquid (162 ml, 95 kcal) or aerated (500 ml, 95 kcal) drink at 0 and 120 min. In Study 2, assessing the effect of N2 O itself, 23 volunteers consumed water saturated with N2 O or with CO2 10 min after a mini-drink (180 kcal). Appetite was quantified by area-under-the curve (AUC) and time-to-return-to-baseline (TTRTB).

RESULTS

Full- and half-size aerated drinks decreased hunger AUC over 4 h by 26 and 50% (P < 0.0001) versus the respective liquid versions. Effects were also sustained significantly longer (TTRTB from 203 to 335 and from 173 to 286 min, respectively). In Study 2, N2 O and CO2 had similar effects on appetite ratings.

CONCLUSIONS

Aeration of foods using appropriate microstructural design has a powerful effect on eating motivations.

Effects of learning and food form on energy intake and appetitive responses

Energy-yielding beverages reportedly contribute to positive energy balance uniquely. They are highly consumed and evoke weaker satiety signaling and dietary energy compensation than solid foods of the same energy content. This study measured the contribution of learning to appetitive sensations and adjustments of energy intake for preloads varying in energy content and food form in lean and obese adults. One-hundred seven participants received four preload trials before and after a dietary intervention in this randomized cross-over trial with the stipulation that lean and obese individuals were evenly assigned to each intervention. The study entailed monitoring appetitive sensations and daily energy intake after consumption of low and high energy beverage and solid food loads on weekly visit days. Preload testing was conducted at baseline, followed by daily ingestion of one load for 14 days and then retesting responses to the four treatments. Lean individuals compensated precisely for the high energy beverage and solid loads from the onset of the study, whereas the obese did not alter eating patterns after consuming the higher energy beverage load. The learning intervention did not have an effect on the responses to the preloads, as responses in both lean and obese participants did not differ from baseline values. Responses to personality and eating behavior questionnaires revealed differences between the lean and obese groups and weakly, but significantly, predicted challenge meal and total daily energy intake. These data suggest that lean and obese individuals respond to energy in beverage form differently, and this is not altered by purposeful daily exposure to loads varying in physical form and energy content for two weeks.

Effects of feeding frequency and dietary water content on voluntary physical activity in healthy adult cats

Low physical activity has been identified as a major risk factor for the development of feline obesity and diabetes. This study aimed to evaluate the effects of increased meal frequency and dietary water content on voluntary physical activity in cats fed to maintain BW. Ten adult lean neutered male cats were used in 2 tests, both crossover studies composed of a 14-d adaptation period, followed by a 7-d measurement of physical activity from d 15 to d 22 using Actical activity collars. Cats were group housed for most of the day, except for times when they were individually housed in cages to access their diet under a 16:8 h light:dark cycle. In Exp. 1, the difference in voluntary physical activity among cats fed 1, 2, 4, or a random number of meals per day were tested in a 4 × 4 Latin square design in 4 individual rooms. In Exp. 2, the effect of increasing dietary water content on voluntary physical activity was tested in a crossover design including a 5-d phase for fecal and urine collection from d 22 to 27. Cats were randomly assigned to 2 rooms and fed a dry commercial diet with or without added water (70% hydrated) twice daily. Activity levels were expressed as "activity counts" per epoch (15 s). In Exp. 1, average daily activity level for 1-meal-fed cats was lower than 4-meal-fed (P = 0.004) and random-meal-fed (P = 0.02) cats, especially during the light period. The activity level of cats during the dark period was greater in 1-meal-fed cats compared with cats fed 2 meals (P = 0.008) or 4 meals (P = 0.007) daily. Two-hour food anticipatory activity (FAA) before scheduled meal times for 1-meal-fed cats was lower (P < 0.001) than for the multiple-meal-fed cats. In Exp. 2, average daily activity level of cats fed the 70% hydrated diet tended to be higher (P = 0.06) than cats fed the dry diet, especially during the dark period (P = 0.007). Two-hour FAA before the afternoon meal for cats fed the 70% hydrated diet was lower (P < 0.05) than for cats fed the dry diet. Cats fed the 70% hydrated diet had greater daily fecal (P = 0.008) and urinary (P = 0.001) outputs and lower (P < 0.001) urinary specific gravity compared to cats fed the dry diet. In conclusion, increased feeding frequency and dietary water content, without changing energy intake or dietary macronutrient composition, appear to promote physical activity, which may aid in weight management in cats.