The Weirdness of Ghrelin


From Tel Aviv University, Dr. Daniela Jakubowicz suggests that eating sweets at breakfast can exert a positive influence for the rest of the day. This possibility is based on a study in which some participants were given low-carbohydrate, low-calorie breakfasts, and others had high-carbohydrate, high-protein breakfasts. With the latter, it appears that people feel fuller for the rest of the day. Consequently, they are not tempted to overeat, and find it easier to resist cravings for sweets.

Here’s the breakdown, as reported by Rachel Rettner:

The study involved 193 obese adults, half of whom were randomly assigned to eat a large, 600-calorie breakfast that included a ‘dessert’ item, such as a cookie, cake or donut. The other half ate a small, 300-calorie breakfast. Both groups consumed the same total daily calories — 1,600 calories for men and 1,400 for women. After 16 weeks of strictly following this diet, both groups had lost about the same amount of weight. However, during a follow-up period in which participants were advised to stick to the diet, but could eat more if they were motivated by hunger cravings, the small breakfast group gained 24 pounds, while the big breakfast group lost 15 pounds, on average.

Immediately, of course, horror was expressed by others. Even nutritionists who believe in a substantial breakfast, which is most of them, don’t want to join any kind of sweets-for-breakfast bandwagon, because sugar sets up a craving for more sugar.

This does not sound like a good childhood obesity solution. Rettner quotes dietician Katherine Tallmadge:

I would never, in a million years, recommend cookies or cake for breakfast.

So a substantial breakfast, containing one-third of the day’s recommended calories, looks like a good idea, but those calories shouldn’t be sugary.

The secret seems to lie in ghrelin, otherwise known as the “hunger hormone.” Humans definitely need it, because it reminds us to eat and keep the organism alive. But when the amount of it rises, ghrelin tells us to eat for hedonic reasons, just for the sheer pleasure of eating, and the results of that can be dire. Less ghrelin = fewer cravings, more ghrelin = more cravings. And what this study seems to indicate is that a big breakfast results in lower levels of the “hunger hormone” in the body. This translates directly to a decrease in food cravings.

Something unusual is going on with this ghrelin factor, according to another nutrition lab, and it’s related to the placebo effect. A study at Yale gave all the participants 380-calorie milkshakes. But the researchers told some of the subjects that they were receiving an “indulgent” treat packed with 620 calories, and told others that they were drinking “sensible” milkshakes with only 140 tiny calories.

Then, they measured the levels of ghrelin in the participants’ bodies — which reacted exactly as if those pretend calorie counts had been real. In other words, Helen Dodson tells us:

People who think they’re indulging when they eat have lower levels of ghrelin.

Now, that is just plain weird. Dodson quotes Alia Crum, the Yale study’s lead author:

The brain was tricked into either feeling full or feeling unsatisfied. That feeling depended on what people believed they were consuming, rather than what they actually were consuming. What was most interesting is that the results were somewhat counterintuitive. Consuming the shake thinking it was ‘indulgent’ was healthier than thinking it was ‘sensible.’ It led to a sharper reduction in ghrelin.

The important question that needs more exploration is, can a person fool herself or himself? Or does the deception have to be imposed from outside? Can a person eat a dish of mashed carrots and pretend really hard that it’s ice cream, and fool her or his own body into deriving more satisfaction from it? Then, theoretically, the body would produce less ghrelin, thereby preserving the person from food cravings for the rest of the day. That would be a skill worth acquiring.

Your responses and feedback are welcome!

Source: “Cake for breakfast? Study says go for it,”, 02/12/12
Source: “To feel full, think ‘treat’ when you eat,”, 06/01/11
Image by jonny2love (Jonny Hughes).

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About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
You can contact Dr. Pretlow at:


Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

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