Eating as a reward – Why do we do it?

Posted on Apr 9, 2013 in Blog | 0 comments

Here is a post from my resident nutritional writer Jennifer Novakovich

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Why do some people have no problems keeping their weight at a healthy range while for others it’s constant struggle? This post will be on eating as a reward and for pleasure, hope you enjoy!

There are strong regulatory mechanisms that maintain our body weight; we eat when our body needs the calories. In modern times though, many people eat not because they’re hungry but because of a hedonic drive; eating, when not hungry and despite large fat reserves, for pleasure. There’s a lot of controversy on whether food can be considered addictive with the neural component being a main argument in favor of food addictions. Readily accessible foods and sedentary lifestyles are major factors for obesity but the interactions between these factors and genetic predispositions are what are really important in the occurrence of obesity.

Food is often used as a reward or as a response to emotions or pain. This response is exaggerated through a lifetime of using food as a reward; when we give kids food for good behaviour we teach them bad behaviours for the future. The reward system will motivate us to eat tasty treats while the hedonic (pleasure) system will encourage us to keep eating. With our current surroundings with an increase in accessibility, advesmall child with icelollyrtisement and palatability, our brains react the way any animal’s brains would react due to our reward and hedonic systems. Many of our attitudes we have towards food comes from our childhoods, this makes it especially important for us to not reward kids with food.

So what do I mean by the reward system? In warm-blooded animals especially (like us), finding and eating food is a daily need that is high on our priority list even in a dangerous environment. Food as rewards is proposed to be the motivation needed to overcome difficult conditions. When seeking food, reward expectancy and effort as well as risk requirements will be accessed with the question ‘will I benefit overall?’ Seeing, smelling and finally tasting the first bite of food will give reward value feedback. Appetite is heightened by things like stomach acid and insulin secretion. Pleasure comes from olfactory (taste) sensations which drive consumption until satiety signals dominate (which can be down-regulated when we chronically over eat). Nutrient sensors in our digestive tract further enhance the reward interpretation after a meal (e.g. mice will learn to prefer sugar over water even when taste sensing is removed). Feelings of satisfaction linger after a meal; a number of sensory and emotional stimuli determine the rewarding experience derived from eating. Food as a reward is an adaptation in animals to enhance our survival.

Overeating can be explained by an over-activation of reward systems and decrease in satiety systems. There seems to be a reward deficiency with defective dopamine signalling in obese individuals (via genetics or non-genetic predispositions early in life or via diets high in sugar and fat or via obesity); increased food intake will occur in attempt to restore their set point for rewards. Obese individuals ‘like’ and ‘want’ palatable foods more than lean individuals (dependent on the effort necessary to get these foods). Obese individuals have a greater hedonic hunger along with a decreased perceived sweetness; ‘liking’ increases with increased sweetness as BMI increases. Clearly, overeating is multifactorial and hard to overcome especially in modern times.

Dieting has been shown to be difficult to adhere to by inducing strong feeling of hunger and cravings. Food deprivation will increase the reward value of foods. Higher-calorie foods will selectively increase the neural activity of the reward related areas of our brains and result in an increase in motivation to eat. A better method for weight loss would be not as restricting and therefore more prolonged; fast weight loss programs are definitely not the way to go when trying to achieve long term weight management.

So how can we overcome eating as a reward? Overeating can only be overcome by practicing self-control, which is hard in today’s day and age; allow yourself goodies every once in a while but limiting its amount. Creating healthy habits can be another powerful tool for reducing the use of food as a reward. Finding other rewards e.g. get a nice haircut or treat yourself to a spa day. Lastly, ensuring balanced meals and adequate calories throughout the day would help overcome overeating.

And some concluding thoughts; in normal circumstances, energy balance is tightly regulated but in modern times mental and emotional factors can overpower these regulations for energy balance. A greater understanding of these interactions can be a valuable tool in future therapies for obesity. Tasty foods are rewarding by the pleasure and satisfaction that is derived from them, which is an easy go-to relief from our increasingly stressful lifestyles. Hopefully this has been an eye opener for the reason we’re compelled to overeat!

Jen

Avena NM, Rada P, Hoebel BG. (2009) Sugar and fat bingeing have notable differences in addictive-like behavior. J. Nutr.;139:623–628.

Berthoud H. (2002) Multiple neural systems controlling food intake and body weight. Neurosci. Biobehav. Rev.;26:393–428.

Berthoud H. (2011) Metabolic and hedonic drives in the neural control of appetite: Who’s the boss? Curr Opin Neurobiol.; 21(6): 888–896.

Berthoud H, Zheng H, and Shin A. (2012) Food reward in the obese and after weight loss induced by calorie restriction and bariatric surgery. Ann N Y Acad Sci.; 1264(1): 36–48.

Ravussin E, Bogardus C. (2000) Energy balance and weight regulation: genetics versus environment. Br. J. Nutr.;83(Suppl 1):S17–S20.

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