If you think of dieting as a long, painful process, new research may change your mind: In the study, researchers found that people who cut calories slept better, were in a better mood and had better sex lives.
For people in the study who were a normal weight or overweight (but not obese), reducing daily calorie intake by 25 percent led to an improved quality of life, found the study, published today (May 2) in the journal JAMA Internal Medicine.
And yes, it also led to weight loss, the researchers found. [The Best Way to Lose Weight Safely]
"We found that normal-weight and mildly overweight people who wish to lose weight need not worry about decreased quality of life," said Corby Martin, the director of the Ingestive Behavior Laboratory at the Pennington Biomedical Research Center in Louisiana and the lead author on the study. Rather, "they can actually expect to feel better," he said.
In the study, the researchers wanted to see if dieting really deserved the bad rap it often gets for making people grumpy and "hangry."
Researchers have hypothesized that calorie restriction "might negatively affect mood, stamina and libido, and increase irritability, particularly among normal-weight people," Martin told Live Science. But few studies have tested this hypothesis, he said.
In the new study, researchers looked at 220 people who all had body mass index (BMI) scores ranging from 22 (which is considered normal) to 28 (which is considered overweight). The participants were divided into two groups: a calorie-restricted group, which included 145 people, and a control group, which included 75 people, according to the study.
People in the calorie-restricted group met with a health coach who helped them follow a lower-calorie diet, Martin said. (The individuals were each advised to cut their daily calorie intake by about 25 percent.) These individuals were also provided with food for the first few weeks so they could learn how to follow the diet, control their portion sizes, and eat foods that were nutritious and filling, Martin said. The control group, on the other hand, received no dietary advice, according to the study.
Throughout the two-year study period, the participants were asked to fill out questionnaires about their mood, quality of life, sexual function and sleep, Martin said.
The researchers found that the individuals in the calorie-restricted group reported improved mood and sexual drive, reduced tension, and improved general health over the course of the study. In addition, the calorie-restricted group lost an average of about 17 lbs. (7.6 kilograms) by the end of the two-year study period, compared with almost no weight change in the control group, according to the study. The researchers also found that cutting calories did not have a negative impact on sleep; rather, people in the control group reported that their sleep quality decreased over the course of the study.
The benefits of calorie-restriction were similar throughout the course of the study, Martin said. While it is true that people feel hungry when they start eating fewer calories, "other studies have shown that dieting can improve quality of life fairly quickly," he said. [Diet and Weight Loss: The Best Ways to Eat]
Martin cautioned that dieting or caloric restriction is not for everyone, however. If a person wants to try calorie restriction, he or she should first speak to a doctor or health professional, Martin said.
Because the study included younger, healthier adults — many of whom had normal BMI scores — the results suggest that approaches "that buffer against possible weight gain may play an important role in [the] growing obesity epidemic," Dr. Tannaz Moin, an endocrinologist at the David Geffen School of Medicine at the University of California, Los Angeles, wrote in an editorial that was published in the same journal as the study.
In other words, a calorie-restricted diet may be used to help prevent obesity. This approach would be similar to the strategies used to prevent many other chronic diseases, such as keeping blood pressure in check in order to help prevent heart disease, Moin wrote.