Weight loss not the only marker of healthy progress

Weight loss alone doesn’t always prove the progress of a patient’s dietary changes and lifestyle plan, according to new research out of Israel. The body’s fat deposits might be more telling of an individual’s health status.

Proof of healthy lifestyle changes aren’t just projected on your bathroom scale, Iris Shai, PhD, and colleagues explained in their study. While weight loss is a good marker of exercise and dietary changes, Shai and her team in Beer-Sheva, Israel, found certain long-term lifestyle shifts can dramatically modify fat deposits in different areas of the body, suggesting these adipose pools are subject to positive change even when a patient’s waistline measurements aren’t budging.

Shai and co-authors of the paper, published this month in the American Heart Association journal Circulation, used MRI technology to plot these changes in fat deposits—a first for the field, according to a release from Ben-Gurion University of the Negev. The researchers randomized 278 sedentary adults with abdominal obesity or dyslipidemia to either an isocaloric, low-fat (LF) diet or a low-carbohydrate Mediterranean (MED/LC) diet for a total of 18 months.

Previous studies, including the New England Journal of Medicine’s DIRECT two-year trial and its four-year follow-up, have proven the efficacy of MED/LC diets in improving cardiometabolic state and reversing carotid atherosclerosis, according to the release. Shai and colleagues took that research a step further in an effort to discern whether weight loss or fat redistribution was responsible for the health effects of a MED/LC regimen.

Seventy-five percent of patients in Shai et al.’s CENTRAL MRI trial were diagnosed with abdominal obesity, according to the paper. These individuals were employed in an isolated workplace and were provided a monitored lunch, free gym pass and guidelines for their dietary restrictions. MRI scans, each with 300 data points, were taken at six and 18 months.

The MED/LC diet, which is high in unsaturated fats and low in carbohydrates, proved significantly healthier than the more traditional, numbers-based LF diet, the authors wrote. Even with just moderate weight loss, patients on the MED/LC diet saw greater reductions in certain fat pools in their bodies, including visceral, intra-hepatic, intra-pericardial and pancreatic fats.

“We learned in this trial that moderate, but persistent, weight loss may have dramatic beneficial effects on fat deposits related to diabetes and cardiovascular diseases,” Shai said in the release.

Hepatic fat deposits were highly affected, seeing 29 percent reductions with a MED/LC diet, Shai and co-authors said, while visceral and intra-pericardial fats followed closely behind, at 22 percent and 11 percent reductions, respectively. Pancreatic fats and femur intermuscular fat deposits were decreased just one to two percent.

“Weighing patients or using blood tests to detect changes hasn’t, until now, given us accurate pictures—literally—of how different fat deposits are impacted disproportionately by diet and exercise,” Shai said. “These findings suggest that moderate exercise combined with a Mediterranean/low carb diet may help reduce the amount of some fat deposits even if you don’t lose significant weight as part of the effort.”