You’re careful about your diet, watch your weight, and spend hours in the gym every week. Yet your blood pressure, cholesterol, blood sugar, and other numbers aren’t budging. What gives?

The problem could be with what you eat, rather than how much you eat — or even how often you exercise.

If being healthy was as simple as “losing weight” or “keeping thin,” our ancient ancestors who lived in times of extreme food scarcity might still be with us today.

It's about inflammation. Inflammation in your body brought on by nutritional deficiencies could be what is derailing your efforts, according to a new study.

Even though many watch their calories and manage to keep their weight down, our Western diet is laden with sugar, fat, and refined grains and lends itself to a variety of nutritional deficiencies. Even thin people can develop high cholesterol, high blood pressure, or high blood sugar.

“It is well known that habitual consumption of poor diets means increased risk of future disease, but clearly this is not a compelling enough reason for many to improve their eating habits,” researcher Bruce Ames, a professor of Biochemistry and Molecular Biology at the University of California, Berkeley, said in a statement.

Participants in the study ate two nutrient bars a day for two months. Changes in their biochemical and physical measurements were recorded. Those who were overweight or obese saw improvements in such biomarkers as cholesterol, glucose, and insulin levels. Some lost weight just by eating the low-calorie nutrient bars without any extra effort on their part. Even lean participants saw metabolic improvements.

Researchers believe the nutrient bars corrected nutritional deficiencies that were causing inflammation in the body, leading to abnormalities in certain biomarkers of health. Eating well can do the same thing.

A diet that includes plenty of whole grains and fruits and vegetables, along with moderate consumption of nuts and seeds, lean sources of protein, and lowfat dairy foods can supply all the nutrients our bodies need, keeping inflammation in check and our blood work in the reference ranges. Avoiding highly processed foods that have been stripped of their nutrients or foods that offer no real nutrition is key, as well.

“If being healthy was as simple as ‘losing weight’ or ‘keeping thin,’ our ancient ancestors who lived in times of extreme food scarcity might still be with us today,” Gerald Weissmann, MD, the Editor-in-Chief of The FASEB Journal, which published the study, added. “This report shows that what you eat is as important, if not more, than how much you eat and how many calories you burn in the gym.”