If skipping breakfast has ever left you with a craving for some high-calorie mac and cheese or a big, juicy burger, a small new study might explain the reason why.

Researchers at the MRC Clinical Science Centre at Imperial College in London found that there is more brain activation in response to high-calorie items when a person has skipped breakfast, compared with when a person has had their morning meal.

"Through both the participants' MRI results and observations of how much they ate at lunch, we found ample evidence that fasting made people hungrier, and increased the appeal of high-calorie foods and the amount people ate," study researcher Dr. Tony Goldstone, M.D., Ph.D., said in a statement.

The study included 21 male volunteers who were asked not to eat anything before coming in for the study for two visits. On one visit, they were fed a 750-calorie breakfast before undergoing an MRI brain scan where they looked at images of high-calorie foods. They were then fed lunch.

The second visit, they weren't fed any breakfast before undergoing the brain scan where they looked at high-calorie foods. After the brain scans, they were fed lunch.

Researchers found that activity in the orbitofrontal cortex -- the part of the brain that plays a part in reward and pleasantness from food -- was different when the participants were fed breakfast, compared with when they fasted from breakfast.

Specifically, researchers found that the orbitofrontal cortex was more activated when the participants hadn't eaten breakfast.

The study was presented at the annual meeting of the Society of Neuroscience; because it has yet to be published in a peer-reviewed journal, its findings should be regarded as preliminary.

The findings back up prior research on negative ways skipping breakfast can affect your body and brain. Click through the slideshow for more:

Loading Slideshow...
  • ...Are Leaner

    A 2003 study in <a href="http://aje.oxfordjournals.org/content/158/1/85.full">the <em>American Journal of Epidemiology</em> </a>showed that people who skip breakfast are 4.5 times more likely to be obese than those who take a morning meal. The study, which included 499 people whose diets were tracked over a year-long period, also showed that <a href="http://aje.oxfordjournals.org/content/158/1/85.full">eating out for dinner and breakfast</a> are linked with obesity risk.

  • ...Are All-Around Healthier

    A study presented in 2003 at the American Heart Association's annual conference showed that not only are breakfast-eaters less likely to be obese, they're also more likely to <a href="http://news.bbc.co.uk/2/hi/health/2824987.stm">have good blood sugar levels</a> and less likely to be hungry later on in the day, BBC News reported. "Our results suggest that breakfast may really be the <a href="http://news.bbc.co.uk/2/hi/health/2824987.stm">most important meal of the day</a>," study researcher Dr. Mark Pereira, of Harvard Medical School at the time, told BBC News. "It appears that breakfast may play an important role in reducing the risk of Type 2 diabetes and cardiovascular disease."

  • ...Feel More Energized

    Eating a breakfast that's high in fiber and carbohydrates could help you feel less tired throughout the day, according to a 1999 study in <a href="http://www.colorado.edu/intphys/Class/IPHY3700_Greene/pdfs/atkins/Holt.pdf">the <em>International Journal of Food Sciences and Nutrition</em></a>. Researchers found that when people ate a high-fiber, low-carb breakfast, they <a href="http://www.webmd.com/diet/fiber-health-benefits-11/fatigue-fighters-six-quick-ways-boost-energy">had more energy</a> throughout the day compared with people who ate a high-fat breakfast, WebMD reported. <em><strong>CORRECTION:</strong> A previous version of this slideshow incorrectly stated that a high-fat, low-carb breakfast was associated with more energy. It has been fixed to say that a high-fiber, low-carb breakfast is associated with more energy.</em>

  • …Have Better Cholesterol Levels

    A study in <a href="http://ajcn.nutrition.org/content/81/2/388.abstract?cited-by=yes&legid=ajcn;81/2/388">the <em>American Journal of Clinical Nutrition</em></a> showed that breakfast-skippers are more likely to have worse cholesterol levels and insulin sensitivity than breakfast-eaters. The study also showed that the breakfast-eaters consume about <a href="http://www.cbsnews.com/2100-500368_162-673419.html">100 fewer calories</a> a day, compared with people who skip their morning meal, CBS News reported.

  • ...Remember Better

    Eating high-energy foods for breakfast could help to <a href="http://www.sciencedirect.com/science/article/pii/019700709190042K">boost short-term memory</a>, according to a study of 319 teens (between ages 13 and 20) in the <em>Journal of Adolescent Health</em>. Researchers also found that eating a high-calorie breakfast actually seemed to <em>hinder</em> concentration.

  • ...Consume More Nutrients

    People who rarely eat breakfast <a href="http://www.ncbi.nlm.nih.gov/pubmed/22125684">consume more fat and fewer nutrients</a> -- like calcium, potassium and fiber -- than regular breakfast-eaters and "often" breakfast-eaters, according to a 2011 study in the journal <em>Nutrition Research and Practice</em>.

  • …Have An Excuse To Eat Healthy Breakfast Foods

    Breakfast-eaters have an excuse to consume healthy breakfast-time foods like oatmeal, eggs, grapefruit and coffee. Oatmeal has been shown in many studies to be <a href="http://www.eurekalert.org/pub_releases/2008-01/uok-ohc010808.php">good for cholesterol levels</a>, and research has also shown that it could help <a href="http://ase.tufts.edu/psychology/spacelab/pubs/MahoneyEtAl.pdf">improve children's memory</a> and attention skills when eaten for breakfast, compared with ready-to-eat cereals. Grapefruit is high in vitamins C and A, and has also been shown in a <em>Clinical Cancer Research</em> study this year to <a href="http://www.ivillage.com/grapefruit-juice-may-give-boost-cancer-treatment-study/4-a-478748">boost the beneficial effects of cancer drugs</a>, HealthDay reported. Eating eggs for breakfast has been linked to <a href="http://www.jacn.org/content/24/6/510.full">increased satiety </a><em>and</em> less food consumed later in the day, compared with eating bagels for breakfast, according to a 2005 study in the <em>Journal of the American College of Nutrition</em>. (The study was funded by the Egg Nutrition Center.) And coffee, of course, has been linked to a <a href="http://www.huffingtonpost.com/2011/10/31/coffee-health-benefits_n_1064577.html#slide=440649">whole host of health benefits</a>, from a decreased risk of depression to a lower risk of some cancers and Type 2 diabetes.

  • How to make Breakfast Shake

    Learn how to start the day with a healthy breakfast, the breakfast shake.