Falling in love is often accompanied by weight loss that was not even thought about or tried for, it just comes as an incidental side effect. Coincidentally, falling in love causes the body to produce oxytocin, at least for half a year or thereabouts.
As we saw with the Rat Park rodents, pleasant company and an interesting environment can create enough sense of well-being to keep a creature from the clutches of addiction. (Except when it cannot, but that is a another class of question.) In chronological order, Childhood Obesity News looks at studies and discoveries about the intersection of this chemical with weight loss.
Way back in 2008, a Japanese study mentioned how previous research “showed that mice that have been knocked out of their oxytocin receptors had eventually become obese without actually increasing their usual food consumption.”
This is interesting because the online forums frequented by overweight and obese people are rife with complaints that it is truly possible to gain weight on a calorie-restricted diet. They are angry about being called liars.
In 2012 the Abstract of another study on energy expenditure stated,
Despite substantial evidence supporting a role of oxytocin in body weight regulation, it remains controversial whether oxytocin neurons directly regulate body weight homeostasis, feeding or energy expenditure…. [O]ur study suggests that oxytocin neurons are required to resist the obesity associated with a high fat diet; but their role in feeding is permissive and can be compensated for by redundant pathways.
Researchers noted that “its ability to reduce body mass extends beyond that of food intake, affecting multiple factors that determine energy balance such as energy expenditure, lipolysis, and glucose regulation.”
Another Abstract noted oxytocin’s “previously-unappreciated diverse functions in regulating social behaviors and metabolic physiology” and summed up all the recent advances in the field as providing “a promising foundation for the therapeutic strategy of developing innovative OXT peptidyl drugs for the treatment of obesity and related metabolic diseases.”
Yet another described itself,
This review assesses the potential central and peripheral targets by which oxytocin may inhibit body weight gain, its regulation by anorexigenic and orexigenic signals, and its potential use as a therapy that can circumvent leptin resistance and reverse the behavioral and metabolic abnormalities associated with DIO and genetically obese models.
In 2015, there was a study whose title said it all: “Chronic oxytocin administration inhibits food intake, increases energy expenditure, and produces weight loss in fructose-fed obese rhesus monkeys.”
Work originally published in French concurred that “the use of this hormone for weight loss in obese patients or as a complementary treatment in diabetic patients seems to be promising.”
A 2016 study started with the propositions that oxytocin somehow limits food intake, and that its potential to improve metabolic control needed to be explored. They had 20 normal-weight men and 18 obese ones to work with. In both groups, “hypothalamic-pituitary-adrenal axis secretion and the postprandial rise in plasma glucose were blunted by oxytocin.” The text says,
Oxytocin markedly reduced hunger-driven food intake in the fasted state in obese but not in normal-weight men, and led to a reduction in snack consumption in both groups, whereas energy expenditure remained generally unaffected. Oxytocin exerts an acutely inhibitory impact on food intake that is enhanced rather than decreased in obese compared with normal-weight men.
(To be continued…)
Your responses and feedback are welcome!
Source: “Oxytocin receptor-deficient mice developed late-onset obesity,” NIH.gov, 06/11/08
Source: “An obligate role of oxytocin neurons in diet induced energy expenditure,” NIH.gov, 09/18/12
Source: “Coming full circle: contributions of central and peripheral oxytocin actions to energy balance,” NIH.gov, 12/27/12
Source: “A New Horizon: Oxytocin as a Novel Therapeutic Option for Obesity and Diabetes,” NIH.gov, 06/01/13
Source: “Role of oxytocin signaling in the regulation of body weight,” NIH.gov, December 2013
Source: “Chronic oxytocin administration inhibits food intake, increases energy expenditure, and produces weight loss in fructose-fed obese rhesus monkeys,” NIH.gov, 12/24/14
Source: “Oxytocin: metabolic effects and potential use for obesity treatment,” NIH.gov, 01/14/15
Source: “Oxytocin’s inhibitory effect on food intake is stronger in obese than normal-weight men” NIH.gov, 08/24/16
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