Cutting calories may reduce the risk of age-related diseases and may even help you live longer, a new small study suggests. 
 
 People in the study who cut their daily calories by 15 percent for two years experienced two potentially beneficial effects compared with people who kept their regular diet: They had a slower metabolism, which is a sign that their bodies were using energy more efficiently, and less "oxidative stress," a process that can damage cells. 
 
 Both a slower metabolism and reduced oxidative stress have been linked with a lower risk of age-related diseases, such as diabetes and cancer, according to the study, published today (March 22) in the journal Cell Metabolism. The researchers think that this is because a slow metabolism leads to less oxidative stress, which, in turn, leads to less damage to cells and organs in the body. 
 
 "Restricting calories can slow your basal metabolism, and if by-products of metabolism accelerate aging processes, calorie restriction sustained over several years may help to decrease risk for chronic disease and prolong life," lead study author Leanne Redman, an associate professor at Pennington Biomedical Research Center at Louisiana State University, said in a statement. 
 
 Still, the study was only two years long, so the researchers can't say whether calorie restriction actually results in a lower risk of age-related diseases or a longer life. More studies that last for longer periods of time are needed to determine this. [Extending Life: 7 Ways to Live Past 100] 
 
 For decades, researchers have observed that calorie restriction tends to prolong life in a number of animal species, but whether it also leads to longer life spans in humans has been unclear. 
 
 In the new study, the researchers examined the effects of calorie restriction on 53 healthy, nonobese men and women ages 21 to 50. The participants were randomly assigned to either a calorie-restriction group or a control group that ate what they wanted. 
 
 After two years, those in the calorie-restriction group lost nearly 20 lbs. (9 kilograms) on average, while those in the control group maintained their weight. 
 
 To look at changes in the participants' metabolism, the researchers used a "metabolic chamber," which is a sealed room that lets researchers precisely measure the number of calories people are burning. 
 
 They found that the people in the calorie-restriction group were burning about 80 to 120 fewer calories per day than would be expected based on their weight alone. This was mostly due to slowed metabolism during sleep. The participants in this group also saw a reduction in markers of oxidative stress. 
 
 Those in the calorie-restriction group didn't experience harmful effects from their diet — they didn't develop anemia, excessive bone loss or, among the women, menstrual disorders. What's more, they actually had improvements in their mood and quality of life, the researchers said. 
 
 Dr. Luigi Fontana, a research professor of medicine at Washington University in St. Louis, called the work a "very nice study," and said the findings confirm that calorie restriction lowers metabolic rate in humans. However, Fontana disagreed with the idea that a lower metabolic rate and reduced oxidative stress are responsible for the longer life spans tied to calorie restriction. Instead, he said some studies show that changes in the way organisms' cells sense nutrients may be responsible. 
 
 But regardless of the reason for the link between calorie restriction and longer life, Fontana said many people in the U.S. could benefit from cutting their calories. 
 
 "In this country, 70 percent of people are overweight or obese," and obesity is tied to a number of diseases, including heart disease and Type 2 diabetes, Fontana told Live Science. And the only way to lower rates of obesity is with calorie restriction and exercise, he said. 
 
 The researchers of the new study say that future research could look at the effects of calorie restriction along with the consumption of certain substances, such as foods with antioxidants, or resveratrol (a compound found in red wine and other foods), which may mimic the effects of calorie restriction. 
 
 Original article on Live Science. 

 You May Live Longer By Severely Restricting Calories, Scientists Say 
 
 Enlarge this image toggle caption VisualField/Getty Images VisualField/Getty Images 
 
 Research has shown that sharp reductions in the amount of food consumed can help fish, rats and monkeys live longer. But there have been very few studies in humans. 
 
 Now, some researchers have found that when people severely cut calories, they can slow their metabolism and possibly the aging process. 
 
 Clinical physiologist Leanne Redman, who headed the study at Pennington Biomedical Research Center in Baton Rouge, says the first challenge was finding people willing to take part. After all, they would have to cut their typical plate for breakfast, lunch and dinner by up to 25 percent. 
 
 And, she says, none of them were overweight. 
 
 Ultimately, she recruited 53 healthy volunteers. One-third ate their regular meals. The rest were on the severe calorie reduction plan for two years. 
 
 "I don't know if you understand the rigor of what it means to do calorie restriction every day," she says, but the volunteers were committed. 
 
 Not surprisingly, the people cutting calories lost quite a bit of weight — on average, 25 pounds. Those in the control group gained as much as 4 pounds. 
 
 But weight loss was not the point. Redman wanted to know whether this dramatic reduction in calories could affect how quickly people age. 
 
 For testing, participants spent 24 hours in special rooms that measured their metabolic rates via gas, oxygen and carbon dioxide and how it changed over time. 
 
 Redman noticed that for those on the restricted diet, their metabolism slowed and became more efficient. 
 
 "Basically it just means that cells are needing less oxygen in order to generate the energy the body needs to survive; and so the body and the cells are becoming more energy efficient," Redman explains. And if less oxygen is needed to burn energy, then dangerous byproducts of that burning — free radicals — can be reduced. 
 
 "Oxygen can actually be damaging to tissues and cells, and so if the cells have become more efficient, then they've got less oxygen left over that can cause this damage," she says. And that damage can accelerate aging. 
 
 The study was published in the journal Cell Metabolism last month. 
 
 Now, these findings don't directly prove that drastic calorie-cutting will actually help people live longer. People would have to be followed for their lifetimes to prove that. But the study did find that blood pressure, cholesterol and triglycerides were lower in the group on severe calorie restriction. When those numbers are high, they can lead to life-shortening diseases. 
 
 The challenge is, most people may not be able to do a severe calorie-restricted diet, or even want to do it. Lowering metabolism can cause other problems. 
 
 Biochemist Valter Longo, who studies longevity at the University of Southern California, says severely restricting calories for a time can mean you're more likely to gain weight in the end. 
 
 "Basically, you have to eat progressively less to maintain the same weight." 
 
 Most Americans struggle with carrying around too much weight, which can cause countless health problems. 
 
 "For most people, if you consider 70 percent of Americans are either overweight or obese, then you can see how, for most people, this would be a big problem," Longo says. It could lead to more "yo-yo dieting," where people who go off the diet eat more and return to their previous weight or even gain more weight. 
 
 He is also concerned about the potential for muscle loss and a weakened immune system in those on severe calorie-restricted diets. 
 
 Instead of chronic calorie restriction, Longo is a proponent of mini-fasts. These are short reductions in calories to just 900 a day for five days a month, which he says have the benefits of fasting without the potentially negative long-term effects. In fact, he wrote the book on it: The Longevity Diet. Longo stresses the importance of eating more fruits and vegetables and less meat. 
 
 It may not ultimately lengthen your life, he says, but it can certainly help you maintain a healthy weight and avoid the kinds of chronic illnesses that can shorten it. 
 
 These practices are not for everyone. If you have a history of eating disorders check with your doctor before starting any new regimen.
– A new study suggests that those who hope to live long lives should start reducing the portions on their plates. The study in Cell Metabolism followed 53 non-obese men and women over the course of two years, some of whom reduced the amount of calories they ate by 15%, reports Live Science. At that point, researchers put the participants through a series of tests. Yes, those who cut calories lost more weight than the control group, though that wasn't the goal, explains NPR. The more interesting discovery is that the calorie cutters showed a marked improvement in their metabolism. In short, it became more efficient. "Restricting calories can slow your basal metabolism, and if by-products of metabolism accelerate aging processes, calorie restriction sustained over several years may help to decrease risk for chronic disease and prolong life," says lead author Leanne Redman of the Pennington Biomedical Research in Baton Rouge. The researchers acknowledge that the study is fairly small and fairly short, but it backs up similar findings in creatures such as rats and monkeys. As for the weight loss, the calories cutters dropped an average of 25 pounds. A scientist not involved with the study points out a potential drawback: Those who severely restrict calories often end up gaining back more weight in the long run, which could end up shortening longevity. (Another study suggests what matters is when you eat.)