Processed food is even more destructive than we thought. Researchers at UCLA discovered that a diet of foods low in fat but high in sugars and refined flours sapped rats’ will and destroyed their motivation to exercise.
“Our data suggest that diet-induced obesity is a cause, rather than an effect, of laziness,” Researcher Aaron Blaisdell said. Blaisdell’s study indicates that the popular belief that laziness causes obesity  is wrong. Instead, it is a poor diet that causes both laziness and obesity.
Rats Lacked Motivation
Blaisdell and his team divided 32 rats into two groups for the study. One group was fed a healthy diet and the other was fed a junk  food diet. Not surprisingly, the rats eating the junk food diet got fatter.
After three months the rats were placed in pens where they had to press a lever several times to get a shot of sugar water. The fat rats were more likely to take long breaks and give up.
“The obese rats really showed impaired motivation,” Blaisdell said. “It is as if the rat is thinking, ‘This is too much work.'”
The study found that processed food impaired the chemistry of the rats’ brains – and not just their overall weight. The skinny rats and fat rats, Blaisdell said, had the same amount of energy.
“The biggest break a lean rat took was about 5 minutes during a 30-minute session,” Blaisdell told The Los Angeles Times. “In obese rats the breaks were much longer — about 10 minutes for the longest breaks.”
Junk Food Affects Our Brain Chemistry
Blaisdell thinks his findings will apply to human beings because, he said, rats and humans are similar in some ways.
“Rats are a great animal model for humans because there is so much overlap in the systems that regulate appetite and metabolism,” Blaisdell said.
That statement should alarm us because Blaisdell believes a diet high in sugars and processed flours literally messes up the chemistry of our brains. In particular, it increases the production of a chemical called dopamine, a process which can sap the will.
“A colleague of mine has found that if you impair the dopamine system in rats, they give up on harder tasks much sooner than rats that had not had an impairment,” he said. “Diets that induce obesity are likely deregulating that dopamine system.”
Sugar Is Addictive
Blaisdell is not the only doctor who thinks sugar can have such an effect on the brain. In a recent New York Daily News article, Dr. Mark Hyman of the Institute for Functional Medicine wrote that sugar is eight times as addictive  as cocaine. Others agree.
“Sugar activates our brain in a special way,” Eric Stice, a neuroscientist at the Oregon Research Institute, told CNN’s Dr. Sajay Gupta in 2012. “That’s very reminiscent of, you know, drugs like cocaine.”
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Stice made that conclusion after scanning human brains with an MRI after people ate sugary food. Among other things he discovered that sugar consumption increases the production of dopamine, which controls the brain’s pleasure center.
Study Shows American Diet is Dangerous
The UCLA study and other research should be a wakeup call for Americans. The science indicates that the standard diet which is high in sugar, low in saturated fat and high in processed flour promotes obesity and leads to other problems, including laziness.
“We are living in an environment with sedentary lifestyles, poor-quality diet and highly processed foods that is very different from the one we are adapted to through human evolution,” Blaisdell said. “It is that difference that leads to many of the chronic diseases that we see today, such as obesity and diabetes.”
There was one more disturbing result from Blaisdell’s study that should be noted here. When he did autopsies on the rats, Blaisdell discovered that the bodies of the rats fed the junk fed diet contained a large number of tumors. He found fewer smaller tumors in the rats that had been on the healthy diet.
That finding supports the research of Dr. Lewis Cantley of Boston’s Beth Israel Deaconess Cancer Service. In 2012, Cantley told Sanjay Gupta that his research indicates that sugar  literally causes cancer by speeding the growth of tumors.