Breakfast, Weight and Metabolism
For weight loss, the importance of breakfast has come into question lately and the unfolding research may play a role in cancer prevention. Knowing what strategies are effective for weight loss is important because too much body fat increases risk for eight cancers, as well as decreasing risk for other chronic diseases.
Health professionals commonly recommend eating breakfast as one important strategy for getting to and staying a healthy weight. That advice has been based largely on observational and population studies that show people who don’t regularly eat breakfast have a higher risk for obesity, type 2 diabetes and heart disease.
But evidence has not been clear whether eating breakfast is a cause of better health or it's only an indicator of a healthy lifestyle. Now, two new studies published in the American Journal of Clinical Nutrition investigate specific outcomes of breakfast on a group of people over a series of months.
One study looked at whether giving a recommendation to eat or skip breakfast for weight loss was effective in helping overweight and obese adults lose weight. Researchers randomly assigned about 300 overweight people to one of three groups: breakfast, no breakfast or control (no recommendation on breakfast).
All participants received a handout on healthy eating (no mention of breakfast). The breakfast group was instructed to eat breakfast before 10 am every day along with a list of healthy breakfast foods. The no breakfast group was instructed not to eat any food or caloric beverages before 11 am.
At the end of 16 weeks there was no significant difference in weight loss between the breakfast eaters or skippers. Compliance was reportedly high with about 93% of participants saying they followed the breakfast/no breakfast recommendations. The authors point out that they did not test breakfast type or timing on weight loss, and you may need a longer amount of time to detect weight loss. They also did not look at metabolic factors.
The second study did investigate metabolism, finding that there was no significant difference in resting metabolic rate, appetite, body fat or markers of heart health between breakfast eaters or fasters. The study lasted six weeks. Named the Bath Breakfast Project, this trial included 33 lean women and men, with an average BMI of 22. Participants were randomly assigned to either eat a breakfast of at least 700 calories or to not eat or drink anything caloric before noon.
The breakfast group did burn more calories through light physical activity in the morning, but they also ate more calories than the no breakfast group. The breakfast group showed more stable blood sugar in the afternoon and evening than the breakfast fasters.
The authors note that more research is needed in overweight, less healthy and less physically active people to determine if metabolic responses are similar to this study.
The Breakfast Outcome
The fact that these studies are trials makes them notable. And they add to the understanding of how breakfast may affect weight, health and potential cancer risk. But there is still a lot more research needed when it comes to breakfast and weight control.
And for reducing risk of cancer, there are many potential benefits to eating that morning meal. A typical breakfast contributes fiber and whole grains, which help prevent colorectal cancer. Breakfast also offers options to add fruit, which contains numerous protective compounds and also links to reduce risk of oral cancers.
Most Americans, kids and adults, are currently not consuming the recommended amounts of fruits and vegetables. Breakfast offers one more opportunity to do this.
For those who don't like to eat breakfast, these studies do suggest that there's no harm for weight loss or metabolism in skipping that morning meal. Many can find a way to take in all the nutrients and healthful plant foods, without overeating, that are part of a cancer protective diet.
Emily J Dhurandhar et al. "The effectiveness of breakfast recommendations on weight loss: a randomized controlled trial." Am J Clin Nutr August 2014 ajcn.089573.
This study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases; the National Heart, Lung, and Blood Institute; Clinical and Translational Research Award grant ; and The Nordea Foundation, a foundation in Denmark giving health-related grants to promote public well-being.
James A Betts et al. "The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults." Am J Clin Nutr August 2014 ajcn.083402
This study was funded by the Biotechnology and Biological Sciences Research Council.