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Here’s why sleeping too little makes you crave junk food

“If you have a Snickers bar, and you’ve had enough sleep, you can control your natural response," says University of Chicago researcher Erin Hanlon. "But if you’re sleep-deprived . . . your ability to resist them may be impaired. So you are more likely to eat it.” / Getty Images

Getting too little sleep has been linked to bad food choices and overeating. Now, scientists say they think they have a better idea of why.

A lack of sleep boosts chemical signals in the body that give us the munchies and make us take greater pleasure in eating — especially things like sweets and salty, high-fat snacks.

That’s according to a University of Chicago study published last week in the journal SLEEP that says it’s a similar effect to what happens when people use marijuana.

“Sleep restriction seems to augment the endocannabinoid system — the same system targeted by the active ingredient of marijuana — to enhance the desire for food intake,” says Erin Hanlon, a U. of C. research associate in endocrinology, diabetes and metabolism.

The study was the first to measure blood levels of the chemical signal endocannabinoid 2-arachidonoylglycerol, known as 2-AG, which usually slowly rise until hitting a peak at early afternoon, after lunchtime, then dropping.

After being allowed no more than four and a half hours in bed, the study participants’ levels of the chemical started the day higher and remained higher than normal until around 9 p.m., and they wanted to eat more.

Erin Hanlon, University of Chicago
Erin Hanlon, University of Chicago

Even after having a meal just two hours earlier that provided almost all the calories they need in an entire day, the 14 sleep-deprived volunteers in the study couldn’t say no to “highly palatable, rewarding snacks” like cookies, candy and chips, the researchers found. Compared to when they got eight hours of sleep, the volunteers, all in their 20s, consumed 50 percent more calories and nearly twice as much fat when they were restricted to about half as much sleep.

Though the study was small and short-term, Hanlon says that, along with other evidence, the takeaway is this:

“If you have a Snickers bar, and you’ve had enough sleep, you can control your natural response. But if you’re sleep-deprived . . . your ability to resist them may be impaired. So you are more likely to eat it. Do that again and again, and you pack on the pounds.”

Finding might lead to better treatment for heart failure

Pieter de Tombe, Loyola University
Pieter de Tombe, Loyola University

Researchers say they’ve found the protein that’s key to how the heart pumps blood — a finding they say could one day result in new drugs being used to treat heart failure.

With heart failure, the heart is too weak to pump out as much blood as flows into it, so it adds muscle mass and beats faster to try to compensate. But that works for only a limited time out. Patients end up being tired, weak and short of breath and develop swelling.

When people get older, the key muscle protein — which, in the heart, helps control contracting and relaxing — gets short. With heart failure, it gets longer — and less effective, according to Pieter de Tombe of Loyola University Chicago Stritch School of Medicine and other researchers at Loyola, the Illinois Institute of Technology and the University of Wisconsin.

De Tombe said the findings, published in the Proceedings of the National Academy of Sciences, “could point the way to new medications to more effectively treat heart failure.”

‘Biological’ age affects chances of cancer, death

The bigger the difference between your biological age and your actual age, the greater the odds are that you’ll die of cancer, according to a new Northwestern University study.

Dr. Lifang Hou, Northwestern University
Dr. Lifang Hou, Northwestern University

“People who are healthy have a very small difference between their biological age and chronological age,” says Dr. Lifang Hou, chief of cancer epidemiology and prevention at Northwestern’s Feinberg School of Medicine, who led the study. “People who develop cancer have a large difference — and people who die from cancer have a difference even larger than that. Our evidence showed a clear trend.

“This could become a new early-warning sign of cancer,” says Hou, who says the difference between biological and chronological age “could be used to develop an early-detection blood test for cancer.”

The findings were based on blood samples collected from 442 people over a 14-year period. Published in the journal EBioMedicine, the study is the first make the link with cancer and death from cancer.

The study found that people who’ll develop cancer are about six months older based on their biological age than their chronological age — and that people who’ll die of cancer are about 2.2 years older.

Biological — or epigenetic — age can be affected by diet, exercise, obesity and exposure to chemicals in the environment.

Now, the scientists are trying to determine whether exercising more and eating healthy can lower a person’s biological age.