Wanting More, Seeing Less: Hunger Reduces Calorie Evaluations

Calorie estimates play an important role in the regulation of food consumption. Lower calorie estimates contribute to increased consumption, and consequently increase the risk of obesity. The current work presents a novel contribution demonstrating the biasing effect of hunger on calorie evaluations. Study 1 (N = 70) was a field study, where participants visiting a cafeteria estimated calories in four baked goods, with measures taken of their hunger level and their having had lunch. Study 2 was a lab study, where half of the participants (N = 65) fasted for five hours prior to the study, and then estimated calories in three baked goods. Study 1 found lower calorie estimations by hungry participants (M = 255.52, SD = 112.55) relative to lower hunger participants (M = 311.94, SD = 135.85): F(1, 67) = 6.07, p = 0.02. In study 2, the average estimated calories was lower for fasting participants (M = 253.11, SD = 126.13) than for non-fasting participants (M = 301.75, SD = 145.26). The studies demonstrate that motivations generated by physical state (hunger) alter calorie evaluations. This finding is surprising given that motivation generally leads to estimating more of a desired quantity. The study also presents a novel domain of biases in calorie estimation. This reduction in calorie estimates due to hunger may occur if calories are assessed relative to needs, or serve to allow people to justify increased food consumption. Accounting for such biases, particularly in cases of low nutrition literacy, is important in order to reduce the overeating that may be generated by calorie estimation biases.

Household food security access, and amidst Covid-19: a study case in Equatorial Guinea

Food is of primary importance for households. Equatorial Guinea (EG) has progressed much in income growth but less in living standard, which includes food security. To situating food–insecurity prevalence in EG, this paper researches household food security-access, and its link-cause to agriculture–considering the Covid-19– using the Household Hunger Scale (HHS). On the data, we surveyed 400 households, imparted in EG rural and urban areas of Bioko Island and the mainland. The results reveal a 2.4 mean for both rural and urban Bioko, placing households at moderate hunger level. On the mainland, rural scores 3.21 (the area most affected), yet falling in moderate hunger level; while the urban scores best 0.64 and stands in the food-safe zone. It derives that diet is rather monotonous and embrace–mainly– carbohydrates rice, bread, cassava, and plantain. A focus on boosting the productivity of staples is paramount for Food security and even national security.

Four Weeks of 16:8 Time-Restricted Feeding on Stress, Sleep, Quality of Life, Hunger Level, and Body Composition in Healthy Adults: A Pilot Study on Wellness Optimization

Introduction: Sustainable methods of dietary lifestyle changes are essential to long term weight loss maintenance and enhancement in overall health and wellness A novel modified alternative method to caloric restriction is Time-Restricted Feeding (TRF), a sub-type of Intermittent Fasting. The purpose of this pilot study was to determine the effect of four weeks of TRF (without caloric deficit) on body composition, stress levels, sleep quality, hunger level, and quality of life. Methods: Sixteen participants, 9 males and 7 females, mean age 34.0 ± 11.7 years, completed the four-week protocol. Fasting program was 16 hours from the time of last meal of the evening to start of first meal the following day. Participants were required to consume their normal daily caloric intake within an 8-hour period. Results: There were significant reductions in mean body fat percentage (26.2±2.4 vs. 25.5±2.6, p=0.01), visceral fat (cm2) (98.2±15.3 vs. 94.1±15.7, p=0.003), body fat mass (kg) (21.6±3.0 vs. 21.0±3.2, p= 0.02), trunk fat (kg) (11.5±1.6 vs. 11.0±1.6, p=0.001) and stress levels (14.1±1.9 vs. 11.0±1.4, p=0.03). There was a significant drop in hunger levels over time (χ2 = 16.4, p=0.001). There were no significant changes in sleep quality or quality of life. Conclusion: TRF may be an effective option to decrease stress, body fat, visceral fat, and obesity-related diseases while not disrupting sleep quality and Quality of Life. Our pilot study demonstrated potential health benefits that could be incorporated by healthcare workers into whole-person wellness programs.

Non-Vocal Behaviors Are More Frequent During the Decisive Negotiation Phases in Barn Owl Siblings

Animals produce vibrations or noises by means of body movements, which can play a role in communication. These behaviors enhance signal transmission or receiver attention and could be specifically used during turn-taking phases of a reciprocal exchange of signals. In the barn owl Tyto alba, nestlings vocalize one after the other to negotiate which individual will have priority access to the impending prey item to be delivered by the parents. Owlets adjust their vocalization to their own hunger level and to their siblings’ vocalization, withdrawing from the contest in front of highly vocal, and hence hungry, motivated nestmates. As sibling negotiation is a multicomponent display, we examined whether body movements could also be part of the negotiation process. To this end, we analyzed whether the vocalizations of one nestling affected its nestmate’s movements in three separate experiments: in natural nests, in the lab, and using a playback procedure. Nestling barn owls move in a variety of ways, such as repeated tapping of the floor with a foot, scratching the floor with claws, or flapping wings. Body movements were more frequent during the turn-taking phases of vocal interactions, when siblings emitted longer calls and at a greater rate. Once an individual monopolized vocal activity, siblings became less vocal and less active. Moreover, owlets produced more noisy body movements during the phases of vocal interactions which are crucial to prevail in negotiation. Non-vocal physical activities might reinforce vocal signals during sibling to sibling (sib–sib) interactions, or reflect owlets’ arousal, in the critical period during which they vocally settle which individual will dominate the competition.

Mating behavior of the Persian boxer mantid, Holaptilon brevipugilis (Mantodea: Mantidae)

The Persian boxer mantid, Holaptilon brevipugilis, is the mantid most recently described from Iran. Here, I present some aspects of the courtship display and mating behavior of this species. I conducted 28 mating trials, quantified the relative frequency of all mating behaviors, and estimated the pre-copulation, copulation, and post-copulation periods. I also compared the effects of frontal vs. lateral approaches of the male for mating success, since frontal approach increases the risk that the male will be seen and cannibalized by the female. In 64% of trials, the male approached the female immediately, regardless of whether the female could see him or not. Copulation was successful in 61% of trials. Male courtship consisted of dorsoventral bending of the male’s abdomen and occurred in 10% of all trials, but only when the female was facing the male. In contrast, trembling of the forelimbs was not associated with copulation, occurred in 10% of all trials, and was always followed by the male moving away from the female. I observed one female cannibalizing a male post-copulation. The Persian boxer mantid might be sexually cannibalistic, but confirming this hypothesis would require further studies, including a focus on female hunger level as a determining factor in sexual cannibalism and in male courtship behaviors.

Hungry People Prefer Larger Bodies and Objects: The Importance of Testing Boundary Effects

Several lab-based studies have indicated that when people are hungry, they judge larger women’s bodies as more attractive, compared to when they are satiated. Thesesatiety-dependent judgements are assumed to provide explanatory power when it comes to the noted cross-cultural differences in attitudes towards women’s adiposity, whereby people who live in regions that are under greater nutritional stress tend to have more favourable attitudes towards bigger bodies. However, it is premature to assume that women’s bodies are the proper or actual domain of the satiety-dependent judgement shifts found within research study testing contexts until stimuli other than female bodies have also been tested: the research programme falls into the trap of confirmation bias unless we also seek out disconfirmatory evidence, and test the boundaries of the effects of hunger. Accordingly, we collected attractiveness judgements of female and male bodies manipulated to vary in size by varying level of adiposity, and objects manipulated to vary in size, from 186 participants who also reported their current hunger level. We found that larger sizes of stimuli in general, and women’s bodies in particular, especially when judged by women, were judged as more attractive by the hungrier participants. We discuss these patterns in the context of the Insurance Hypothesis, the Environmental Security Hypothesis, and the impact of hunger on acquisition.

Hunger and stress monitoring system using galvanic skin response

In the world, roughly more than 3 million people are affected by muscle power loss diseases which cause lack of communication. Further, this lack of communication is a severe problem with hunger and stress, which sometimes proves to be fatal. It is essential to monitor physical parameters such as hunger and mental stress of the patient. To observe hunger and stress, galvanic skin response (GSR) sensor is a most preferred method because it measures the conductance of skin due to sweating. We have designed new hunger and stress monitoring system (HS-MS) that helps patients and their caretakers to monitor stress and hunger level. HS-MS is two electrodes system that attaches to two fingers (index and middle) of the patient and monitors starvation and tension. According to the response of the sensor, caretakers can identify hunger and even the mental stress conditions of the patient. In all, 35 patients were examined using HS-MS system and 20 of them were used as a control. Overall system accuracy was found out to be 86.6% and response time of HS-MS 5 seconds. Sensitivity with respect to hunger and stress was about 99.9% and 73.3% respectively. Thus HS-MS can be identified as a helpful tool to provide comfort to the patient easily and can be used in hospitals or homes with lonely elderly people.

Effect of Variation in Nestling Hunger Levels on the Begging Behaviour of Nestlings and the Provisioning Behaviour of Adult American Kestrels

Little is known about how variation in nestling begging intensity influences the behaviour of adult raptors and how responses of adult males and females to such variation might differ. Our objective was to manipulate the begging intensity of nestling American Kestrels (Falco sparverius) and examine the responses of adults. We studied 12 pairs of American Kestrels nesting in nest boxes from 1 March to 1 July 2014 at the Blue Grass Army Depot, Madison County, Kentucky. Nest boxes were modified with a separate compartment for a camcorder to record nestling behaviour, and a second camcorder was placed outside the nests to monitor adult behaviour. To manipulate nestling hunger levels, 12 to 26-day-old nestlings in six nests were deprived of food for 24 h and those in the other six nests were fed until satiated. At each nest, we alternated control (no treatment) and treatment (fed or food deprived) days over a 4 day period to minimise the possible effect of nestling age on adult and nestling behaviour. Nestling begging intensity differed among treatments, with nestlings in food-deprived nests begging with greater intensity after food deprivation and those in fed-treatment nests begging with less intensity after being fed. Adult male and female American Kestrels provisioned nestlings at similar rates, with both sexes feeding nestlings at higher rates after food deprivation and at lower rates after fed treatments. Thus, the begging behaviour of nestling American Kestrels varied with hunger level, and adult American Kestrels responded by adjusting provisioning rates. Although the response of adults to nestling begging suggests that natural selection might favour ‘dishonest’ begging to obtain more food, the potential costs of ‘dishonest’ begging, such as attracting predators, reduced immunocompetence, and loss of indirect fitness benefits if such begging negatively impacts siblings and parents, may outweigh any possible benefit.

Juvenile honest food solicitation and parental investment as a life history strategy: a kin demographic selection model

Parent-offspring communication remains an unresolved challenge for biologist. The difficulty of the challenge comes from the fact that it is a multifaceted problem with connections to life-history evolution, parent-offspring conflict, kin selection and signalling. Previous efforts mainly focused on modelling resource allocation at the expense of the dynamic interaction during a reproductive season. Here we present a two-stage model of begging where the first stage models the interaction between nestlings and parents within a nest and the second stage models the life-history trade-offs. We show in an asexual population that honest begging results in decreased variance of collected food between siblings, which leads to mean number of surviving offspring. Thus, honest begging can be seen as a special bet-hedging against informational uncertainty, which not just decreases the variance of fitness but also increases the arithmetic mean.Author SummaryParent-offspring communication is a fascinating problem that captures the attention of scientist and layman alike. Parent-offspring interaction is the first interaction with non-self in the life of most young birds and mammals. The future life success of such young animals crucially depends on how successful they are in interacting and communicating with their parents. This communication has different functions: it is important for the offspring to solicit food from the parent and it is important for the parent to be informed about the state (hunger level) of the offspring. There is an optimization problem on top of this level: the parent has to ‘decide’ what part of the available resources should be allocated to the offspring and what part should she keep for herself. Here we show in a probabilistic model that the honest phenotype -where offspring beg only if they are hungry-has a greater growth rate than a selfish type - which begs regardless of its hunger level. This result holds in asexual populations; here honesty serves as a reduction uncertainty for the parents. The improved decision making of the parents -in turn-increases the survival of the offspring as well.

Investigating the Proximity Effect in a Competitive Food Environment: A study protocol

Obesity and overweight levels are rising nationally, despite recent governmental advertising campaigns being implemented to tackle the prevalence rise at a population level. Therefore, alternative approaches should be investigated in an effort to reduce obesity prevalence rises. One such approach modifies the external cues and the environment where decisions about food are made, and it is commonly known as Choice Architecture (CA). The proximity effect is a strategy within CA that could reduce overall calorie consumption by placing healthier foods at relatively closer distances compared to unhealthy foods. Amongst studies examining the proximity effect, only one so far has explored the simultaneous presentation of healthy and unhealthy foods, referred to as a competitive food environment. As unhealthy foods are often preferred over healthy foods, the current study aims to investigate whether food choice can be overridden by varying degrees of proximity effect and whether key factors such as visual salience, perceived effort, BMI, age, food preference, and executive function moderate this effect. A sample of 48 undergraduate students will participate in a laboratory experiment, believing they are taking part in a relaxation study. Participants will be simultaneously presented with two bowls of food: A healthier fruit selection and an unhealthier chocolate option, each varying according to proximity (either 20cm or 70cm). The participants will be asked to complete a questionnaire measuring multiple factors that may influence food consumption, such as perceived effort and hunger level. The primary outcome of the study is the amount of each food consumed (in grams) depending on relative proximity, with the secondary outcome exploring whether the effect of the latter is influenced by the key moderators. The proposed study explores the proximity effect in a competitive food environment, an area rarely explored in research but high in real-world applicability. If a greater amount of the most proximal food is consumed in each condition, regardless of food healthiness, the intervention can be scaled up to a novel field experiment to further evaluate the effectiveness of the proximity effect in reducing calorie intake.