Unpalatable truths: Commitment to eating meat is associated with strategic ignorance of food-animal minds

Animal minds are of central importance to debates about their rights and welfare. Remaining ignorant of evidence that animals have minds is therefore likely to facilitate their mistreatment. Studying samples of adults and students from the UK and US we found that, consistent with motivational perspectives on meat consumption, those who were more (vs. less) committed to eating meat were more motivated to avoid exposure to information about food-animals’ sentience (Studies 1), showed less interest in exposure to articles about intelligent food animals (Studies 2a and 2b), and were quicker to terminate exposure to internet pop-ups containing information about food-animals’ minds (Studies 3a and 3b). At the same time, those who were more (vs. less) committed to eating meat approached information about companion-animals’ minds (Studies 2a-3b) and unintelligent food animals (Studies 2a and 2b) in largely the same ways. The findings demonstrate that, within the UK and US, the desire to eat meat is associated with strategies to avoid information that is likely to challenge meat consumption.

Two-Month administration of Methylphenidate improves olfactory sensitivity and suppresses appetite in individuals with obesity

Introduction: Olfaction contributes to feeding behaviour and is modulated by changes in dopamine levels. Methylphenidate (MPH) increases brain dopamine levels and has been shown to reduce appetite and promote weight loss in patients with attention deficit hyperactivity disorder. The objectives of this study were to test the effect of MPH on olfaction, appetite, energy intake and body weight on individuals with obesity. Methods: In a randomized, double-blind study, 12 participants (age 28.9±6.7 yrs) (BMI 36.1±4.5 kg/m2) were assigned to MPH (0.5mg/kg) (n=5) or Placebo (n=7) twice daily for 2 months. Appetite (Visual Analog Scale), odour threshold (Sniffin’ Sticks®), energy intake (food menu), and body weight (DEXA scan) were measured at day 1 and day 60. Results: MPH intake significantly increased odour threshold scores (6.3±1.4 vs. 9.4±2.1 and 7.9±2.3 vs. 7.8±1.9, respectively; p=0.029) vs. Placebo. There was a significantly greater suppression of appetite sensations (desire to eat (p=0.001), hunger (p=0.008), and prospective food consumption (p=0.003)) and an increase in fullness (p=0.028) over time in the MPH vs. Placebo. Conclusions: MPH suppressed appetite and improved olfactory sensitivity in individuals with obesity. These data provide novel findings on the favourable effects of MPH on appetite and weight regulation in individuals living with obesity.

A Change of Scenery: Does Exposure to Images of Nature Affect Delay Discounting and Food Desirability?

Previous research suggests that exposure to nature may reduce delay discounting (the tendency to discount larger future gains in favor of smaller immediate rewards) and thereby facilitate healthier dietary intake. This pre-registered study examined the impact of online exposure to images of natural scenes on delay discounting and food preferences. It was predicted that exposure to images of natural scenes (vs. images of urban scenes) would be associated with: (i) lower delay discounting; (ii) higher desirability for fruits and vegetables (and lower desirability for more energy-dense foods); and (iii) delay discounting would mediate the effect of nature-image exposure on food desirability. Adult participants (N = 109) were recruited to an online between-subjects experiment in which they viewed a timed sequence of six images either showing natural landscape scenes or urban scenes. They then completed measures of mood, delay discounting (using a five-trial hypothetical monetary discounting task) and rated their momentary desire to eat four fruits and vegetables (F&V), and four energy-dense foods. There was no statistically significant effect of experimental condition (natural vs. urban image exposure) on delay discounting or food desirability. Bayes factors supported the null hypothesis for discounting (BF01 = 4.89), and energy-dense food desirability (BF01 = 7.21), but provided no strong evidence for either hypothesis for F&V desirability (BF01 = 0.78). These findings indicate that brief online exposure to images of nature does not affect momentary impulsivity or energy-dense food preference, whereas for preference for less-energy dense foods, the evidence was inconclusive.

Effect of using cassava as an amylopectin source in low protein diets on growth performance, nitrogen efficiency and postprandial changes in plasma glucose and related hormones concentrations of growing pigs

This study was aimed to explore the effect of using cassava as an amylopectin source in low protein (LP) diets on growth performance, nitrogen efficiency and postprandial changes in plasma glucose and related hormones concentrations of growing pigs. Three animal experiments were included in the present study. Treatments included corn-soybean meal LP (Corn LP), corn-cassava-soybean meal LP (Corn + Cassava LP), and cassava-soybean meal LP (Cassava LP). The in vitro digestion proved that Corn + Cassava LP and Cassava LP diets induced more rapid starch digestion and glucose release, compared with Corn LP diet. The results of animal experiments are as follows: Cassava LP diet caused the most rapid changes in plasma glucose and relevant hormones concentrations after a meal. And it decreased the concentrations of fasting plasma insulin, glucagon, and leptin concentrations compared with other treatments (P < 0.05). These modulationes above led to a strong desire to eat and increased feed intake and then weight gain in growing pigs fed Cassava LP diet. Besides, feeding Cassava LP diet caused diarrhea, increased noxious gas release from feces, and increased concentrations of fecal isobutyrate and isovalerate (P < 0.05). Compared with Corn LP group, Corn + Cassava LP group showed significantly decreased urinary nitrogen (P < 0.05) and improved post-absorptive amino acid utilization efficiency. In conclusion, the use of cassava as an amylopectin source in LP diets could modulate glucose absorption and related gut secreted hormones secretion, subsequently strengthened the desire to eat, improved growth performance, and enhanced nitrogen efficiency in growing pigs.

Glycaemic and Appetite Suppression Effect of a Vegetable-Enriched Bread

Bread, a frequently consumed food, is an ideal vehicle for addition of ingredients that increase nutrient density and add health benefits. This experimental cross-over study sought to test the effect of a vegetable-enriched bread (VB) in comparison to commercial white bread (WB) and wheatmeal bread (WMB) on serum glucose, insulin response and subjective appetite suppression. On three separate occasions, 10 participants (23 ± 7 years) visited the laboratory and consumed after an overnight fast, in random order, a 75 g serve of WB, WMB or VB. Venous blood samples drawn twice before (0 min) and at 15, 30, 45, 60, 90 and 120 min after consumption of the bread were analysed for glucose and insulin. Participants rated their subjective feelings of hunger, fullness, satisfaction and desire to eat on a 150 mm Likert scale. The mean glucose iAUC over 120 min was not different among the breads. The mean insulin iAUC for the VB was significantly lower than the WB and WMB; difference VB and WB 12,415 pmol/L*minutes (95% CI 1918, 22,912 pmol/L*minutes, p = 0.025) and difference VB and WMB 13,800 pmol/L*minutes (95% CI 1623, 25,976 pmol/L*minutes p = 0.031). The VB was associated with a higher fullness feeling in the participants over the 120-min period. The consumption of VB was associated with less insulin release and higher satiety over 120 min which may be related to the higher fibre content and texture of VB. The role of vegetable and fruit fibres such as pectin in bread and insulin response should also be further explored.

Effect of the perception of breakfast consumption on subsequent appetite and energy intake in healthy males

Purpose This study aimed to assess the effects of consuming a very-low-energy placebo breakfast on subsequent appetite and lunch energy intake. Methods Fourteen healthy males consumed water-only (WAT), very-low-energy, viscous placebo (containing water, low-calorie flavoured squash, and xanthan gum; ~ 16 kcal; PLA), and whole-food (~ 573 kcal; FOOD) breakfasts in a randomised order. Subjects were blinded to the energy content of PLA and specific study aims. Venous blood samples were collected pre-breakfast, 60- and 180-min post-breakfast to assess plasma acylated ghrelin and peptide tyrosine tyrosine concentrations. Subjective appetite was measured regularly, and energy intake was assessed at an ad libitum lunch meal 195-min post-breakfast. Results Lunch energy intake was lower during FOOD compared to WAT (P < 0.05), with no further differences between trials (P ≥ 0.132). Cumulative energy intake (breakfast plus lunch) was lower during PLA (1078 ± 274 kcal) and WAT (1093 ± 249 kcal), compared to FOOD (1554 ± 301 kcal; P < 0.001). Total area under the curve (AUC) for hunger, desire to eat and prospective food consumption were lower, and fullness was greater during PLA and FOOD compared to WAT (P < 0.05). AUC for hunger was lower during FOOD compared to PLA (P < 0.05). During FOOD, acylated ghrelin was suppressed compared to PLA and WAT at 60 min (P < 0.05), with no other hormonal differences between trials (P ≥ 0.071). Conclusion Consuming a very-low-energy placebo breakfast does not alter energy intake at lunch but may reduce cumulative energy intake across breakfast and lunch and attenuate elevations in subjective appetite associated with breakfast omission. Trial registration NCT04735783, 2nd February 2021, retrospectively registered.

Empleo de semillas como ingrediente saciante: chía y sésamo

Debido al gran aumento de la prevalencia del sobrepeso y obesidad en todo el mundo, ha aumentado el inte- rés de estudio de los mecanismos que llevan a la población a un desequilibrio energético, aumentando su peso corporal de forma excesiva. El control de la ingesta de energía va determinado por la percepción de la saciedad durante y después de las comidas. Hay ciertos alimentos que por sus características nutricionales (cantidad de fibra, hidratos de carbono, proteína y grasa) pueden influenciar de forma positiva sobre el apetito (disminuyen- do el deseo por la comida). Por ello sería una buena estrategia nutricional ver cuáles de los alimentos presenta mayor relación sobre la saciedad. Realizamos un ensayo clínico cruzado aleatorizado con un periodo de lavado de 5 días, como mínimo. El objetivo del presente estudio fue evaluar el efecto de las semillas de sésamo y chía (por su gran cantidad de fibra soluble) sobre la saciedad (introducidas junto con yogur en el desayuno). La muestra estaba formada por 18 voluntarios. Cada voluntario realizó los 3 tipos de desayunos de forma aleatoria: (café con leche o té con leche + tostada con aceite de oliva y sal) + (yogur, yogur con chía o yogur con sésamo). Antes del desayuno tuvieron que rellenar una encuesta sobre apetito (VAS) y después 7 más (a los 15, 45, 75, 105, 135, 165 y 195 minutos tras el desayuno). Para valorar el efecto saciante de las semillas, se analizaron las preguntas del VAS que presentan relación directa con la saciedad, y se realizó un ANOVA. Los resultados mos- traron que no había diferencias estadísticamente significativas (p>0.05) entre las semillas estudiadas. Nowadays, there is a high prevalence of overweight and obesity around the world, so the inter- est in studying the mechanisms that lead the population to an energy imbalance has increased. The control of energy intake is determined by the perception of satiety during and after meals. There are certain foods that, due to their nutritional characteristics (amount of fibre, carbohydrates, protein and fat), can positively influence the appetite (decreasing the desire to eat). Thus, it would be a good nutritional strategy to see which foods have a greater satiety effect. We performed a randomi- zed crossover clinical trial with at least 5-days washout period. The objective of the present study was to evaluate the effect of sesame and chia seeds (due to their large amount of soluble fibre) on satiety. The sample consisted of 18 volunteers. Each one performed the 3 types of breakfasts randomized: (coffee with milk or tea with milk + toast with olive oil and salt) + (yoghurt, yoghurt with chia or yoghurt with sesame). Before breakfast they had to fill out an appetite survey (VAS) and then 7 more (at 15, 45, 75, 105, 135, 165 and 195 min after breakfast). To assess the satiating effect of the seeds, the questions of the VAS directly related to satiety were analysed, and ANOVA was performed. The results showed that there were no statistically significant differences (p>0.05) between seeds.

A change of scenery: Does exposure to images of nature affect delay discounting and food desirability?

Previous research suggests that exposure to nature may reduce delay discounting (the tendency to discount larger future gains in favour of smaller immediate rewards) and thereby facilitate healthier dietary choices. This study examined the impact of online exposure to images of natural scenes on delay discounting and food preferences. It was predicted that exposure to images of natural scenes (vs. images of urban scenes) would be associated with (i) lower delay discounting; (ii) higher desirability for fruits and vegetables (and lower desirability for more energy-dense foods); and (iii) delay discounting would mediate the effect of nature-image exposure on food desirability. Adult participants (N = 109) were recruited to an online between-subjects experiment in which they viewed a timed sequence of six images either showing natural landscape scenes or urban scenes. They then completed measures of mood, delay discounting (using a 5-trial hypothetical monetary discounting task) and rated their momentary desire to eat four fruits and vegetables (F&amp;V), and four energy-dense foods. There was no statistically significant effect of experimental condition (natural vs. urban image exposure) on delay discounting or food desirability. Bayes factors supported the null hypothesis for discounting (BF01 = 4.89), and energy-dense food desirability (BF01 = 7.21), but provided no strong evidence for either hypothesis for F&amp;V desirability (BF01 = 0.78). These findings indicate that brief online exposure to images of nature does not affect momentary impulsivity or energy-dense food preference, whereas for preference for less-energy dense foods, the evidence was inconclusive.