Title
Lifestyle-Induced Visceral Fat Loss as a Key Target for Durable Cardiometabolic Health: MRI-Based 5- and 10-Year Follow-Up After Two Clinical Trials
Summary
Long-term follow-up after two lifestyle trials found that reductions in visceral fat, more than overall weight loss, were linked to sustained improvements in cardiometabolic health and a lower future risk of type 2 diabetes, even when many participants regained weight.
Background
Excess body fat is not distributed equally across the body. Fat stored around the abdomen, especially visceral adipose tissue, sits deep inside the abdomen and surrounds internal organs. Unlike fat under the skin, visceral fat is strongly associated with insulin resistance, abnormal cholesterol levels, inflammation, fatty liver disease, and a higher risk of type 2 diabetes and cardiovascular disease.
For many years, weight loss has been the main goal in lifestyle programs. However, clinicians and researchers increasingly recognize that where fat is lost may matter as much as how much weight is lost. A person may regain body weight after a diet or exercise program, yet still retain some of the metabolic benefits if harmful fat depots, particularly visceral fat, remain reduced.
This study examined whether the body-fat changes achieved during two randomized controlled trials were associated with better long-term health after the structured interventions ended.
What the Two Trials Studied
The follow-up analysis combined participants from two earlier lifestyle trials:
CENTRAL, conducted from 2012 to 2014, tested dietary strategies for weight loss together with structured physical activity.
DIRECT-PLUS, conducted from 2017 to 2018, tested different Mediterranean-style diets, including a standard Mediterranean diet, a low-carbohydrate version, and a green Mediterranean diet enriched with polyphenol-rich foods, also combined with physical activity.
Both trials focused on lifestyle change rather than medication or surgery. Participants were guided to improve diet quality and increase physical activity, which led to measurable reductions in abdominal and ectopic fat during the intervention period.
How the Follow-Up Was Done
Researchers invited participants back 5 and 10 years after the original trials were completed. They reassessed body composition and metabolic health using magnetic resonance imaging, or MRI, a highly accurate way to measure different fat depots.
The MRI evaluation included:
Visceral adipose tissue, the fat around internal organs
Deep subcutaneous adipose tissue, the deeper layer of fat under the skin
Superficial subcutaneous adipose tissue, the more superficial layer of fat under the skin
Intrahepatic fat, or fat stored in the liver
Intrapancreatic fat, or fat stored in the pancreas
In addition to imaging, participants underwent clinical follow-up measurements. Researchers also assessed diet adherence, physical activity, and metabolic markers related to insulin resistance and diabetes risk.
Main Findings
A total of 366 of 381 eligible participants were successfully reached for follow-up, a very high follow-up rate of 96%.
The most important finding was that even though many participants regained overall body weight over time, some of the favorable changes in abdominal fat were partly preserved.
Specifically:
Waist circumference remained better than expected compared with baseline, despite weight regain.
Visceral fat, deep subcutaneous fat, and superficial subcutaneous fat retained part of the reduction achieved during the original intervention.
In contrast, liver fat and pancreatic fat did not remain improved over the long term. These fat stores were largely regained, and in the case of pancreatic fat, the increase was even more pronounced.
This pattern suggests that abdominal fat depots respond differently over time after lifestyle intervention. Some may be more durable targets than others.
Why Visceral Fat Matters Most
The study showed that every 10% reduction in visceral fat achieved during the intervention was associated with better long-term metabolic outcomes after follow-up. Similar associations were also seen for superficial subcutaneous fat and intrapancreatic fat, but visceral fat stood out as the strongest and most clinically meaningful target.
After adjusting for later weight change, adherence to a Mediterranean diet, physical activity scores, and other relevant measures, each 10% intervention-induced loss of visceral fat was linked to improvements in:
Metabolic Score for Insulin Resistance
Composite risk score
Metabolic Syndrome Severity Score
These scores are commonly used to reflect the overall burden of cardiometabolic risk. Better scores indicate improved insulin sensitivity, more favorable metabolic health, and lower risk of future disease.
Most notably, only visceral fat loss was independently associated with a substantially lower risk of developing type 2 diabetes during follow-up. A 10% reduction in visceral adipose tissue was linked to a 28% lower risk of incident type 2 diabetes, corresponding to a hazard ratio of 0.72.
In practical terms, this means that among people who achieved meaningful visceral fat loss through diet and exercise, the later risk of diabetes was significantly reduced even years after the original program ended.
Clinical Interpretation
These findings reinforce an important message: the number on the scale does not tell the whole story.
Two people may lose the same amount of weight, but one may lose a larger proportion of visceral fat while the other loses more subcutaneous fat or lean tissue. The metabolic benefits are likely to differ. Visceral fat is more biologically active and more harmful than fat under the skin because it is closely connected to inflammatory pathways, abnormal lipid metabolism, and impaired glucose handling.
The study suggests that lifestyle programs should not only aim for weight loss but also prioritize fat redistribution and reduction in harmful internal fat stores.
Implications for Diet and Exercise
The interventions in both trials were based on diet quality, structured physical activity, or both. Although the specific dietary patterns differed, all were designed to improve long-term health through sustainable behavior change.
This study supports several practical lessons:
Improving diet quality can reduce harmful abdominal fat even without dramatic weight loss.
Regular physical activity appears to contribute to healthier body-fat distribution.
Mediterranean-style eating patterns may help support metabolic health over time.
Lifestyle changes can have benefits that last beyond the active intervention period.
Importantly, the data also show that some benefits persist despite partial weight regain, which is encouraging for patients who struggle to maintain long-term weight loss. Even when body weight returns somewhat, the body may still be metabolically healthier than before if visceral fat remains lower.
What This Means for Patients
For patients, the takeaway is reassuring and actionable:
Do not judge success only by body weight.
Waist size and abdominal fat matter greatly for health.
Sustainable diet and exercise habits may provide long-lasting benefits, even if weight loss is not permanent.
Targeting abdominal fat, especially visceral fat, may be a better marker of health improvement than focusing only on kilograms lost.
This is especially relevant for people with prediabetes, insulin resistance, metabolic syndrome, fatty liver disease, or a family history of type 2 diabetes.
Limitations to Consider
Like all follow-up studies, this research has limitations. It was observational during the post-trial period, meaning that after the original trials ended, participants were not randomly assigned to maintain or lose fat. Therefore, the results show strong associations, but they cannot prove cause and effect on their own.
Also, participants were originally enrolled in controlled clinical trials and may have been more motivated than the general population. That can make the findings somewhat harder to generalize to all adults.
Even so, the high follow-up rate, MRI-based measurements, and long duration of observation make the findings especially valuable.
Bottom Line
This 5- and 10-year follow-up of two lifestyle trials suggests that diet and exercise can produce lasting cardiometabolic benefits, even when weight is regained later. The most important long-term target appears to be visceral fat loss rather than weight loss alone.
A modest 10% reduction in visceral fat through lifestyle change may cut the future risk of type 2 diabetes by nearly 30%. For durable metabolic health, the location of fat loss matters as much as the amount of weight lost.
Study Registration
CENTRAL: NCT01530724
DIRECT-PLUS: NCT03020186
