Moderate exercise combined with a Mediterranean and low carbohydrate diet may help reduce the amount of some fat deposits, according to a long-term study.
The study, published in the journal Circulation, used MRI imaging technology for the first time to plot the diverse changes in an array of body organ fat storage pools during 18 months of Mediterranean-low-carb (Med-LC) and low-fat diets with and without moderate physical exercise.
The study, led by researchers from Ben-Gurion University of the Negev (BGU) in Israel and Harvard University in the US, sought to assess how distinct lifestyle strategies would impact specific body (adipose) fat deposits.
To map these deposits, they collected an unprecedented quantity of whole body MRI data in benchmark six-month and 18-month scans, each with 300 data points, from moderately overweight to obese men and women.
"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 do not lose significant weight as part of the effort," said Professor Iris Shai from BGU, the primary investigator of the study.
In the study, even with only moderate weight loss, the Med-LC diet was found to be significantly superior to a low- fat diet in decreasing some of the fat storage pools, including visceral (abdominal deep), intra-hepatic (liver), intra-pericardial (heart), and pancreatic fats.
However, fat deposits in renal-sinus (kidney), femoral- intermuscular or the cervical (neck) were only altered by weight loss and not by specific lifestyle strategies.
The various fat deposits exhibited highly diverse responsiveness to the interventions, along with moderate, long-term, weight loss, researchers said.
In general, the greatest fat deposit decreases were hepatic (minus 29 per cent), visceral (minus 22 per cent) and intra-pericardial (minus 11 per cent).
Pancreatic and femur intermuscular fat deposits were only reduced one to two per cent, researchers said.
"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.
A Mediterranean diet, rich in unsaturated fats and low in carbohydrates, was a more effective strategy than an iso- caloric low-fat diet to dramatically reverse morbid fat storage sites, researchers said.
The 18-month trial included 278 sedentary adults in an isolated workplace, with a monitored lunch provided.
The participants were randomised to iso-caloric low-fat or Med-LC diet - 28 grammes of walnuts per day with or without an added moderate workout at least three times weekly and a supervised, free gym membership.
The "study demonstrates that improving nutritional quality and being physically active can improve cardio- metabolic risk markers through changes in visceral/ectopic fat deposits that are not reflected by changes in body weight alone," Shai said.