Scientists at the University of Liverpool are presenting data this week at the European Congress on Obesity demonstrating that children are indeed influenced mightily by food ads they see on television.
The researchers had 60 kids (aged 9-11) watch various TV ads followed by a cartoon show followed by a presentation of food. Some of the ads were for toys, others wre for food products. After the ads and the cartoons, the children increased their food intake substantially with the overweight increasing theirs the most. Normal weight kids upped their intake by 84 percent whereas the obese kids increased theirs by 134 percent. The merely overweight fell in the middle with a consumption of 101 percent of their normal intake. These figures are pretty significant since even the normal weight kids ate almost double their normal amount and the obese almost triple. (I’ve read only the press release, which doesn’t tell how much is ‘normal’ for these kids. I would assume that the researchers had the kids fast for a given period of time, then let them watch the cartoons, then provided them with food and measured consumption. But I don’t know this for sure.)
What I find most interesting about this study based what I read in the press release is the types of foods that the normal weight kids overate compared to the obese.

It was also found that weight dictated food preference during the experiment. Food of differing fat contents was made available to the children to eat at their own will, ranging from high fat sweet snacks to low fat savoury products. The obese group consistently chose the highest fat product – chocolate – whereas the overweight children chose jelly sweets which have a lower fat content, as well as chocolate.

A couple of things about this…
The press release doesn’t tell us what the normal weight kids chowed down on, although it is implied that they may have hit the low-fat savory snacks (which are typically also low in carbohydrates). But it’s clear that the researchers have a fat phobia and figure that the obesity in these kids comes from the fat they eat. Both the chocolate and the jelly sweets are crawling with carbohydrates. Of those, however, there is no mention.
The press release makes it seem as if the food commercials drove the obese kids to eat chocolate and the slightly less obese kids to eat jelly sweets. I would argue that the ads drove the kids to eat not a specific food, but the foods that each kid liked the best. If a kid is hungry and you give him/her a wide array of foods, it would make sense that he/she would go after the favored foods. It would be nice to know what foods the food ads were promoting.
Perhaps these food choices are simply a mirror of what got these kids overweight in the first place.
There is some physiological basis for this hunger after the food ads. There are two phases of the release of insulin: the first phase and the second phase. The first phase is also called the cephalic phase because it originates in the brain. Let me explain.
Elevated blood sugar is so toxic that the body had developed multiple methods to keep it from going too high. One of these ways is to get the insulin into the blood at about the same time as the sugar from a sugary meal gets there so that the system is prepared and doesn’t have to wait for the elevated blood sugar to send the message to the pancreas, then for the pancreas to get the message, make and release insulin. There is already some insulin there waiting.  The body brings this about by the cephalic phase of insulin release.
If you walk by a bakery and smell the fresh bread baking or if you open a box of warm donuts of if someone sets a plate of cake and ice cream before you (or if you write about these things – it’s happening to me right now), your brain says, Uh oh, sugars coming, better get ready. The brain sends a quick message to the pancreas to start releasing insulin. Then when the sugar from the fresh baked bread, the warm donuts, or the cake and ice cream hits your bloodstream insulin is already there waiting for it so that sugar doesn’t go as high as it otherwise would. Once the blood sugar level does start going up (because the cephalic phase doesn’t release enough insulin to handle the whole load of sugar), it sends the signal to the pancreas for more insulin, which is the second phase of insulin secretion.
It’s easy to see what happens if you walk by the bakery and don’t eat the bread or if you don’t eat the warm donuts or cake and ice cream. Suddenly you’ve got a little squirt of insulin on board without the expected blood sugar increase. What does this excess insulin do? It acts on the blood sugar that’s already there, which may be at a normal level. When it does, the insulin quickly reduces the blood sugar. And, as I’ve written about before, a falling blood sugar makes you hungry almost faster than anything else. That’s why you get hungry when you smell the fresh bread or see and smell the warm donuts or have someone give you a plate of cake and ice cream (or write about it). You get hungry even if you weren’t hungry to begin with because your cephalic phase of insulin release drops your blood sugar. (You can even just sit and think about food and have the same thing happen.)
These kids had the perfect set up for hunger. They saw the food ads, then they watched the cartoon for 4-5 minutes (I’m assuming it was a typical cartoon), allowing the cephalic phase of their insulin release to knock their blood sugars in the dirt, then they were provided with food. Is it any wonder they ate more than expected?
The question is do these food ads drive kids via the above physiology to eat more at their regularly scheduled meals or is it only when their blood sugar is at a nadir driven by the insulin response due to the food ads?
The research does show – at least the way I interpret it – that if you’re going to let your kids watch TV shows that have a lot of food ads, it’s probably best to not make unlimited snacks available to them during the time they’re watching and immediately after. Of give them such low-carb snacks as jerky or nuts. The little buggers probably won’t like it, but, hey, they’re kids. They’ll get over it.  They don’t know you have their best interests at heart.


  1. Just a thought – any chance of just walking by the bakery a few times a day and losing weight?
    You don’t lose weight when your insulin is up; you lose it when your insulin is down.
    But you could always give it a try and report back.

  2. Encourage me a bit here….I’m on insulin…does this mean I’ll not be able to lose weight because of the insulin….which I would not need if I could lose weight…..but I’m doomed because I need the insulin…..which would be unnecessary if I could drop the weight…
    I’m feeling a bit trapped….Got any words of encouragement?
    Hi Ressy–
    You’re kind of in a tough spot. There is no doubt that insulin, including the injectable kind, will make it difficult to lose weight. I’m assuming you’re a type II diabetic on insulin. If so, you need to work with a physician skilled in getting people to reduce their insulin levels. Sadly, most doctors these days put people on large doses of insulin, then tell them to eat carbs to keep from going into insulin shock. As the patients eat more and more carbs, their weight goes up as does their insulin requirement. At the next visit the doc increases the insulin and tells them to eat more carbs. It becomes a vicious cycle.
    The amount of insulin that a normal person secretes daily is about 30 units. So, if you’re taking more than 30 units, you’re probably taking too much.
    Get a copy of Dr. Richard Bernstein’s book. It will help you greatly.
    Hope this info helps.

  3. What’s the best way to handle times when your cephalic phase insulin has already been released, say, after reading a blog that mentioned smelling fresh bread, warm donuts, and cake and ice cream several times (Thanks Doc… 😉 ).
    To hazard a guess, I’d think eating a small snack of protein and fat instead, to release some glucagon to balance out the insulin until the insulin levels dropped again?
    I guess the best way is not to read such garbage.
    You’re right. If you feel hungry, just eat a low-carb snack. It’ll do the trick without the second phase of insulin release.

  4. I constantly wonder why psych researchers (I’m assuming this was a psychology study at heart) spend money on what any economist could tell them for free. Advertising works. If it didn’t, no large company with a history of advertising would ever do it. What’s more, I only need to think back to my college years to realize the suggestive power of television ads: I am unsure how much pizza I bought, but it was generally right after an ad for same on the TV, or a box walking through the lounge destined for another. Thanks for the post which reiterated the science behind the experience that most know.
    PS- For anyone who would suggest that the relationship between TV adverts and kids is in need of study, lemme suggest this. The industry (advertising + those who market to kids) continue to advertise. Beyond that, the fact that there is a whole industry. Add to that the increasing numbers of kids shows, networks, movies, etc. Recall, a TV show is merely something to keep you watching ads. Really. That’s how the people who buy and program TV look at them (pay cable is the exception, which is why HBO’s shows tend to be of better quality).
    Last thought: Companies don’t do things, over the long haul, that don’t return value. I’m sure we can find exceptions, but companies that sell things don’t sell losers for long, and they don’t pursue marketing that doesn’t return on investment over the long run as well. That way lies the road to ruin. It doesn’t require deep study.
    Hey Max–
    I’ll answer your question as to why psych researchers spend money on such studies. Because they get grants. Where do they get these grants? Typically from your employer. Where does your employer get the funds to deal out for such idiocy? From all of us out here in taxpayer land.

  5. Dr. Mike,
    Do you think that the cephalic phase of insulin release compromises the intended effects of intermittent fasting? In other words, is there sufficient insulin released to cause the fast to end? I’m fasting this morning (a 15 hour overnight fast from my last meal eaten last evening), and sure as heck someone brought in donuts. I didn’t eat any, but I assume my brain prepositioned some insulin. Does the insulin mean my fast has ended and I won’t derive any further benefit by continuing to the 15th hour? Another thought/question. I stopped eating things like donuts years ago, well before I started low carbing. It is a VERY rare occurance for me to eat things like donuts, ice cream, etc. I don’t feel like I really crave these things when I see them, I simply pass them by. Do you think over time this could have resulted in my having less of a cephalic insulin response? Many thanks!
    Hi Thomas–
    First, I don’t think a tiny squirt of insulin is going to hamper or end your fast, so don’t worry about it. Second, if the food doesn’t appeal to you, your brain is smart enough to figure out that you’re probably not going to eat it, and consequently won’t stimulate an insulin response.

  6. Does the cephalic phase kick in from the taste of Asparatame/Splenda?
    Indeed it does. Which is one of the reasons for the studies showing that subjects randomized to diet drinks don’t lose much, if any, weight as compared to those on regular soft drinks.
    The subject is worthy of a longer post some time.

  7. The amount of insulin that a normal person secretes daily is about 30 units. So, if you’re taking more than 30 units, you’re probably taking too much.
    Get a copy of Dr. Richard Bernstein’s book. It will help you greatly.
    Hope this info helps.
    Thanks! My dh and doc and myself (RN BSN) are alwaying trying to avoid the situation of feeding the insulin….
    I understand it’s gonna be difficult. Right now we are adjusting insulin to a lower carb diet but not less than 30 gm and adding in more exercise…it’s like hitting a moving target sometimes with that insulin dose…which is more than 30 units right now. There has gotta be that sweet spot where the amount of carbs and type of carbs and exercise and dose of Lantus all work together. Once we get those ratios down then all can be adjusted in parallel…. we think. A pump might be in my future…
    Sometimes the insulin makes me so hungry….I have to tell this olde body….”if you are that hungry take something off the left hip”….
    Off to the bookstore!
    Good luck. I hope you enjoy Dr. Bernstein’s book. I think it’s a real Godsend to anyone with diabetes.
    Keep me posted.

  8. “I’ll answer your question as to why psych researchers spend money on such studies. Because they get grants. Where do they get these grants? Typically from your employer. Where does your employer get the funds to deal out for such idiocy? From all of us out here in taxpayer land.”
    As someone who was once looking at doing a PhD and becoming a research professor, you’d think there would be some intellectual curiosity beneath the psych researcher, into knowing a given thing. Truth be told, I wanted to do the PhD to be a B-school professor, but the research I was designing was centered on something I actually wanted to understand better. So, maybe there are some mercenary psych researchers out there who just go where the money is, but that seems kind of unlikely.
    I am employed by the Department of Labor. I’m sure someone here has given a grant for some psych research at some point, but that’s not much of what my employer is up to at any given moment. WE certainly didn’t fund this piece of garbage. Which isn’t to say that we never fund garbage (they do, I don’t), but we’re generally pretty far from consumer research beyond the Consumer Price Index, which is very far removed from psych research, and actually useful to people far beyond government. Any rate, thanks for sharing.
    Currently reading “Perfectly Legal” which is the book that makes me most angry about the federal government and makes me most want to earn $330K/year or more and dodge taxes like the top 1%. Tax policy needs a major change. Major.
    Hi Max–
    I read “Perfectly Legal” when it first came out in hardback a few years ago. I’m sure I had a much different take than you. My thought was not ‘how do we stop this travesty’ but ‘how can I get myself in a position where I can take advantage of these loopholes.’ Sadly, it’s not by spending a couple of hours per day on this blog.

  9. Dr. Mike,
    Does caffeine (coffee, tea, non caloric drinks )induce a cephalic phase?
    Some people think it does. I’ve never seen any hard data on it though. (Which doesn’t mean that such data doesn’t exist – it only means that I haven’t seen in.) I don’t particularly think it does. The artificial sweeteners in the diet soft drinks absolutely do, but not the caffeine so much, if at all.

  10. I can swear by Dr. Bernstein’s book Diabetes Solution. It’s helped me get off and stay off meds as a Type II diabetic. The thing that terrifies me about the governments obsession with fat is when the idea arises every once in a while about starting to tax high fat food to try and get consumers to consume less of it. Since fat makes up a major portion of my diet that is gonna cost me a lot of money if it ever happens.
    Hi Max–
    I hope it takes them a while to get around to taxing fatty foods. By the time they do, maybe there will be a new nutritional paradigm.
    Keep your fingers crossed.

  11. As someone who was not born in this country, it perplexes me to see how the goverment runs our lives and how most people clamor for more gov’t intervention, contrary to the principles upon which this great nation was founded. Astonishing the culture of blame and lack of personal accountability so prevalent in most segments of society. The government doesn’t need to tax any food group, just eliminate the subsidies.
    Hi Carlos–
    Good observation. The cycle here starts with a demand for government intervention, which, of course, leads to a government screw up, which then leads to a demand for government intervention to fix the screw up (which, naturally, the massed don’t remember was a government screw up in the first place because the politicians have cleverly found a scapegoat), which then starts the cycle again.

  12. Here’s a weird question.
    I’m trying to get into the mindspace needed to release insulin by vividly imaginging, behind-the-eyes and with full sensory experience, walking past a bakery. I’m actually making myself sick and ruining my breakfast doing this, so I’m going to stop and ask you about it.
    To me, bread, donuts, cake and ice cream are pica, not food. Has there ever been any studies on committed (1+ year) low-carb and/or grain-free dieters and the effect of stimuli on them?
    Purely an academic interest, I know, but an interesting one nonetheless.
    Hi Lochlyn–
    I don’t think there have been any studies done on the subject. At least I haven’t seen one if there has been. Wanna volunteer?

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