Patients on GLP-1s often report reduced \u201cfood noise,\u201d but understanding of how these drugs affect motivation around food is incomplete. Wayne Pratt, PhD, shared with Psychiatric Times about his latest research on how glucagon-like peptide 1 (GLP-1) signaling may dampen the pro-feeding influence of reward circuitry in the brain.1 Pratt noted that human functional magnetic resonance imaging studies showed that GLP-1 receptor agonists altered responses to food cues in reward-related regions, including parts of the striatum.2 He characterized “food noise” as primarily a change in appetitive motivation (the drive to seek and work for food), while indicating that GLP-1 drugs appeared to influence both appetitive and consummatory motivation through homeostatic brainstem and hypothalamic systems as well as reward-related circuitry. He emphasized that food motivation is multidimensional, shaped by learned cues, accessibility, and effort, and that clinicians and patients need more evidence on the long-term benefits and adverse effects of GLP-1 drugs, including after discontinuation.<\/p>\n
Psychiatric Times: Your lab found that GLP-1 receptor activation in the nucleus accumbens blunted binge-like feeding driven by mu-opioid stimulation. What might that suggest about why patients on GLP-1s report reduced “food noise”?<\/p>\n
Wayne Pratt, PhD: My lab has long been interested in how the brain combines signals about physiological need, learned experience, and food reward to control food seeking and consumption. Part of our work has been to better understand how opioid signaling in brain reward regions affects eating and motivation. We and many other laboratories have shown that stimulating mu-opioid receptors in the rat nucleus accumbens strongly promotes eating, particularly of highly palatable foods, such as those high in sugar and fat hat are commonly consumed during binge episodes.<\/p>\n
It is, of course, unlikely that mu-opioid receptor stimulation of the nucleus accumbens is equivalent to the \u201cfood noise\u201d that humans report. However, our findings are consistent with the possibility that GLP-1 signaling can dampen some of the pro-feeding influence of reward circuitry. Importantly, human fMRI studies have shown that GLP-1 receptor agonists can alter responses to food cues in reward-related regions, including parts of the striatum. That does not mean our rat model is equivalent to human food noise, but it does suggest that both the basic and human literatures point toward a role for GLP-1 signaling within brain reward circuitry in dampening the motivational pull of food.<\/p>\n
PT: Do you see food noise best understood as a change in appetitive motivation, consummatory motivation, or both?<\/p>\n
Pratt: Appetitive motivation refers to the drive to seek out and work for access to food, whereas consummatory motivation occurs once food is obtained and is often measured by the amount of food consumed. \u201cFood noise\u201d seems to fall primarily into the former category, with people reporting that their thoughts often center on food. This can be driven by internal signals, such as hunger, or by external cues that have become associated with food and the desire for food.<\/p>\n
One reason GLP-1 drugs are especially interesting is that they appear to influence both appetitive and consummatory motivation without, so far, producing the kinds of psychiatric problems that limited some earlier pharmacological strategies for treating obesity. GLP-1 signaling appears to impact homeostatic brain circuits, including brainstem and hypothalamic systems that monitor physiological state and contribute to satiety. But it can also influence reward-related circuitry involved in the motivational value of food; those systems normally interact. How hungry we are changes how rewarding food is, and learned food cues can motivate eating even when physiological need is relatively low.<\/p>\n
So, although \u201cfood noise\u201d seems most closely related to appetitive motivation, the current evidence suggests that GLP-1 drugs can influence both appetitive and consummatory aspects of food motivation. We are still working out how much of their clinical effect depends on each of those mechanisms, and how those effects are distributed across the brain and peripheral systems.<\/p>\n","protected":false},"excerpt":{"rendered":"Patients on GLP-1s often report reduced \u201cfood noise,\u201d but understanding of how these drugs affect motivation around food…\n","protected":false},"author":2,"featured_media":944281,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[64,63,137],"class_list":["post-944280","post","type-post","status-publish","format-standard","has-post-thumbnail","category-health","tag-au","tag-australia","tag-health"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/944280","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=944280"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/944280\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/944281"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=944280"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=944280"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=944280"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}