Control Of Food Intake In Humans Research Articles

Poster #T112 IDENTICAL PATTERN OF HEDONIC AND AFFECTIVE REACTIVITY TO DAILY-LIFE SOCIAL STRESS AMONG PATIENTS WITH PSYCHOTIC DISORDER AND HEALTHY INDIVIDUALS

The involvement of endogenous opioids in control of human food intake and appetite was investigated in a double-blind placebo-controlled study using a single, 2.5 mg oral dose of the opioid receptor antagonist, nalmefene. Ratings of the pleasantness of the smell and the taste, but not the appearance, of a number of foods was significantly lower in nalmefene-treated subjects. The magnitude of this effect was greater in food items independently rated as highly palatable. Caloric intake of a buffet-style meal was 20% lower in nalmefene-treated subjects, with the proportional reduction in intake of individual food items also depending on their palatability. These results lend further support to recent suggestions that opioids are involved in reward-related aspects of ingestion.

Short and long-term energy intake patterns and their implications for human body weight regulation

Adults consume millions of kilocalories over the course of a few years, but the typical weight gain amounts to only a few thousand kilocalories of stored energy. Furthermore, food intake is highly variable from day to day and yet body weight is remarkably stable. These facts have been used as evidence to support the hypothesis that human body weight is regulated by active control of food intake operating on both short and long time scales. Here, we demonstrate that active control of human food intake on short time scales is not required for body weight stability and that the current evidence for long term control of food intake is equivocal. To provide more data on this issue, we emphasize the urgent need for developing new methods for accurately measuring energy intake changes over long time scales. We propose that repeated body weight measurements can be used along with mathematical modeling to calculate long-term changes in energy intake and thereby quantify adherence to a diet intervention and provide dynamic feedback to individuals that seek to control their body weight.

Human SH2B1 mutations are associated with maladaptive behaviors and obesity.

Src homology 2 B adapter protein 1 (SH2B1) modulates signaling by a variety of ligands that bind to receptor tyrosine kinases or JAK-associated cytokine receptors, including leptin, insulin, growth hormone (GH), and nerve growth factor (NGF). Targeted deletion of Sh2b1 in mice results in increased food intake, obesity, and insulin resistance, with an intermediate phenotype seen in heterozygous null mice on a high-fat diet. We identified SH2B1 loss-of-function mutations in a large cohort of patients with severe early-onset obesity. Mutation carriers exhibited hyperphagia, childhood-onset obesity, disproportionate insulin resistance, and reduced final height as adults. Unexpectedly, mutation carriers exhibited a spectrum of behavioral abnormalities that were not reported in controls, including social isolation and aggression. We conclude that SH2B1 plays a critical role in the control of human food intake and body weight and is implicated in maladaptive human behavior.

External cues in the control of food intake in humans: The sensory-normative distinction

We review the history of “external cues” as an important factor in the control of human food intake. We begin with Schachter's proposal that obese individuals are especially (and perhaps exclusively) responsive to external food cues and examine subsequent modifications and challenges to that model and the decline and resurgence of research on external cues. We introduce a distinction between normative and sensory external cues. Normative cues (e.g., portion size) refer to indicators of appropriate intake, whereas sensory cues (e.g., palatability) refer to the hedonic appeal of the food. We propose that normative cues affect everyone, whereas sensory cues, while affecting everyone, have a more powerful effect on some types of individuals (e.g., the obese) than on others.

Imprecise control of human food intake

Imprecise control of human food intake

Lower pleasantness of palatable foods in nalmefene-treated human volunteers

The involvement of endogenous opioids in control of human food intake and appetite was investigated in a double-blind placebo-controlled study using a single, 2.5 mg oral dose of the opioid receptor antagonist, nalmefene. Ratings of the pleasantness of the smell and the taste, but not the appearance, of a number of foods was significantly lower in nalmefene-treated subjects. The magnitude of this effect was greater in food items independently rated as highly palatable. Caloric intake of a buffet-style meal was 20% lower in nalmefene-treated subjects, with the proportional reduction in intake of individual food items also depending on their palatability. These results lend further support to recent suggestions that opioids are involved in reward-related aspects of ingestion.

Plans by Katherine Porikos for long-term studies of the role of caloric dilution in the control of human food intake

Plans by Katherine Porikos for long-term studies of the role of caloric dilution in the control of human food intake

Animal Behavior and Internal Drives

Animal Behavior and Internal Drives