“Our research showed that people experience a dramatic decline in cravings for sweet foods when they eat breakfast,” said Heather Leidy, an assistant professor of nutrition and exercise physiology. “However, breakfasts that are high in protein also reduced cravings for savory – or high-fat – foods. On the other hand, if breakfast is skipped, these cravings continue to rise throughout the day.”
According to findings published in the Nutrition Journal, eating initiates a release of dopamine, a brain chemical involved in moderating impulses and reward, including food cravings. The reward response is an important part of eating because it helps to regulate food intake, said Leidy.
“Dopamine levels are blunted in individuals who are overweight or obese, which means that it takes much more stimulation – or food – to elicit feelings of reward; we saw similar responses within breakfast-skippers,” she said.
“To counteract the tendencies to overeat and to prevent weight gain that occurs as a result of overeating, we tried to identify dietary behaviors that provide these feelings of reward while reducing cravings for high-fat foods. Eating breakfast, particularly a breakfast high in protein, seems to do that.”
High protein vs high carb
The research was welcomed by Dr Mitch Kanter, executive director of the Egg Nutrition Center, who said told us: “Over the past few years we have funded a number of studies that looked at the impact of breakfast in general, and high protein breakfast in particular, on feelings of hunger and satiety. Most of these studies have indicated that high protein breakfasts promote satiety more so than high carbohydrate breakfasts. Dr. Leidy’s research provides a potential mechanism for how this phenomenon might work from a biological perspective.
“Understanding mechanisms can ultimately give researchers the ability to better control outcomes which, in this case, can lead to better dietary advice in the fight against overweight and obesity.”
The research was funded by the Beef Checkoff Program, the Egg Nutrition Center and the Margaret Flynn Award from the University of Missouri.
The new study has particular implications for teens, with the Centers for Disease Control and Prevention (CDC) reporting that many teens skip breakfast. The Missouri study included 20 young women with an average age of 19 and an average BMI of 28.6 kg/m2. The women were randomly assigned to eat breakfasts containing normal protein (13 grams of protein), high protein (35 grams of protein) or to skip breakfast for six consecutive days.
Results showed that blood levels of homovanillic acid (HVA), the main dopamine metabolite, increased in both breakfast meals, compared with the breakfast skipping, with the high protein breakfast leading to the sustained increases in HVA.
In addition, post-meal cravings for sweet and savory foods were decreased in the breakfast groups, with the greater reductions observed in the high protein group.
“HVA concentrations were positively correlated with the protein content at breakfast,” they added.
“In the US, people are skipping breakfast more frequently, which is associated with food cravings, overeating and obesity,” said Leidy. “It used to be that nearly 100% of American adults, kids and teens were eating breakfast, but over the last 50 years, we have seen a decrease in eating frequency and an increase in obesity.”
Source: Nutrition Journal
“A randomized crossover, pilot study examining the effects of a normal protein vs. high protein breakfast on food cravings and reward signals in overweight/obese “breakfast skipping”, late-adolescent girls”
Authors: H.A. Hoertel, M.J. Will, H.J. Leidy