How Food Variety Promotes ObesityMonday, March 16, 2009
A major characteristic of our current foodscape is the wide range of foods easily available to us. For most of us, neither geography nor seasons are a significant barrier to variety.
What role does this easy access to variety in foods play in the obesity epidemic – especially in kids?
I have previously blogged on the downside of variety from an obesity perspective.
Further insights into how variety increases the risk for obesity comes from a study by Leonhard Epstein and colleagues from the University at Buffalo, Buffalo, NY, USA, published in this month’s issue of the American Journal of Clinical Nutrition.
The study deals with how variety influences habituation, or the decrease in behavioral response to a stimulus after repeated exposure over time. In the context of food, to put it very simply, habituation would lead to decreased intake of that food – almost as if the subject gets “bored” with that food and loses interest – thereby reducing caloric intake.
Previous studies have shown that variety increases food intake both in adults and children, but this study focused on whether obese kids are particularly prone to eating more and wether there is a difference in their susceptibility to a high-variety diet compared to non-obese kids.
The rather complex study did clearly reveal several important findings:
1) Obese kids take longer to habituate to new foods – they therefore tend to eat more than lean kids.
2) The impact of variety on excess food intake is particularly seen with high-energy density foods (although there is also some increased intake with low-energy density foods).
3) Distraction (e.g. tv-viewing) can delay habituation and/or speed the recovery of motivation to eat after habituation.
The bottom line is simple: variety promotes overeating particularly in obese kids, who tend to have later habituation – distraction (as in TV viewing or computer games) is bad as it leads to increased caloric intake and “resets” appetite – both together is particularly treacherous.
Given its apparent importance, it will be interesting to see how limiting variety can be harnessed to reduce caloric intake in folks trying to manage their weight – not a tasty message for the food industry, where variety reigns king.
Monday, March 16, 2009
Your post today reminds me of my first year at the University of Calgary, when I ate in the residence cafeteria 2-3 times a day for the entire year. There were very limited food choices, and by the end of the year, I could barely finish a single meal because I had so little appetite. The week I moved out of residence (or whenever I was eating away from the cafeteria) my appetite miraculously returned. I always blamed it on the quality of the cafeteria food, but it’s interesting to know there could be more to it than that. As usual, very interesting post, and thanks for pointing out the AJCN article!
Monday, March 16, 2009
So does this mean the message to “feed young children a variety of foods so that they don’t become picky eaters ” is a myth perpetuated by the Food Industry?
It appears to be a rather complex issue. Give children a variety of healthy low-density foods (ie. veggies) a limit their variety (and amount) of high-density “junk” foods????
And to Travis in the above post, I used to work for catering at U of C while I was a student there, and I can totally agree to your experience… although I blame it on the quality of food!
Tuesday, March 17, 2009
[…] contribute to food allergies (obese kids have been shown to eat a greater variety of foods – see yesterdays post in this regard) – or do food allergies contribute to obesity? Or are both obesity and allergies […]
Oops…forgot to say great post! Looking forward to your next one.
Tuesday, March 17, 2009
TV affects eating not just by distraction.
TV has ads for food and resaurants which immediately make people hungry. A study of the effect of TV would have to include what was watched, including ads, as well as just the fact that time was spent watching TV.
Ads can also make a difference in how nutritious food is perceived – for example, the ads that tell you veggies are yucky unless they are slathered with a glop of fatty cheese.
It’s hard to become bored with food when just watching a sit-com or the news means you’ll be seeing food, especially bad food, in the most exciting and captivating way an ad man can create.
Wednesday, April 8, 2009
TV is sedentary – non- interactive- regular meal times coincide with news and family gatherings- TV dinners -TV adverts – TV has trained viewers to respond – HUGE hyponotic effect – half time – put kettle on – finish dinner before movies – soaps in a pub – everything we do is reflected on TV – early BBC radio made us use imagination and go out and explore – TV has made us dumbed down dummies that never leave the couch- fat consumers bred to consume crap junk food rubbish – TV has conspired with big business and banks to rip us off and make us lose our own ability to make decisions!