The Benefits of Cutting Just 300 Calories
The health benefits of calorie restriction have been known since the 1930s. Now a new study from Duke University, published this month in the journal, The Lancet Diabetes & Endocrinology, provides further evidence that when even healthy people cut just 300 calories from their food intake a day, they will notice significant improvements in their health. This includes weight reduction, lower risk of diabetes, dementia, and cardiovascular disease (CVD), and lower inflammation levels throughout the body.
Our family practice doctors at Cohen Medical Associates in Delray Beach understand how tough dieting can be, and indeed, some participants in this study dropped out because they found it too difficult to continue.
But if you’re motivated, cutting 300 calories a day isn’t especially difficult: It’s the equivalent of 30 potato chips, once slice of pizza, or two chocolate chip cookies. And the benefits can be striking.
Researchers recruited 218 healthy adults, ages 21 to 50, to participate in the two-year study. They randomly assigned roughly two-thirds of those, or 143 people, to follow a diet that amounted to a 25 percent reduction in the calories they normally ate. The remaining 75 participants were allowed to eat as they typically would, serving as the control group.
The researchers soon learned that adhering to the strict diet proved challenging to many, if not most, of the participants, even though they also received behavioral counseling to help them stick with it. Nevertheless, the calorie-restricted group did the best they could, cutting their daily intake by an average of about 12 percent, or 300 calories.
The results were significant. The calorie-restricted group lost an average of 16 pounds, 71 percent of which was fat, and experienced “significant and sustained” 24 percent reductions in markers for CVD (blood pressure, plasma lipids, C-reactive protein, and glucose measures).
Biomarkers measured also suggested significant reductions in inflammation. Inflammation has been tied to not only a greater risk of diabetes, CVD, cancer, and stroke, but also premature aging throughout the body, as well as the cognitive decline associated with dementia and Alzheimer’s.
“Clearly what surprised us was the magnitude of response in people that already have normal parameters, are young, and have a normal weight,” Dr. William Kraus, a preventive cardiologist and lead author of the study, said in a statement.
And despite the ongoing debate about which diet is best—low-fat, high-carb, no-carb, etc.—the eating regimen of the participants encompassed the major food groups.
“We didn’t alter the proportion of carbohydrate, fat, or protein—we just reduced the calorie content,” Kraus said.
One factor the study did not take into account was exercise or lack thereof because daily exercise or even regular movement is difficult to measure outside a clinical setting over the long term.
The researchers also did not measure clinical indicators for arterial plaque buildup, or atherosclerosis.
Finally, the small sample size and relatively short duration (nine years) means that more research is needed to determine whether the results would hold with a larger group of people over a longer time frame.
“Exercise and diet are the two most profound and easily implemented interventions we have in our environment that can reduce our cardiovascular risks,” Kraus said. “There aren’t five drugs on the market when combined that could approach what we saw in this study from moderate calorie restriction.”
It’s long been known that obesity contributes to a host of diseases, including CVD and cancer. Still, Kraus admitted the weight loss resulting from the calorie reduction couldn’t account for all the benefits seen by researchers in the study.
“It’s not all just due to the weight. There is something else about restricting calories that seems to have benefits on cardiometabolic factors that we don’t really understand,” he said.
This is underscored by the fact that many of the participants were of normal weight at the beginning of the study, yet they also improved their health biomarkers.
It’s difficult but not impossible to reduce calorie intake. Just watch what you eat, and try to identify a handful of calories you don’t really need.
Kraus recommends not eating after dinner.
“People come to my clinic and tell me they have a bowl of ice cream before they go to bed and I just have a fit because those calories are not going to be used—they’re going to be stored—and it’s excess caloric intake they don’t need.”
As always, if you have any questions about your diet, be sure to discuss it with us.