Effect of Moderate Diet-Induced Weight Loss and Weight Regain on Cardiovascular Structure and Function
Key result
Diet-induced weight loss improves LV mass, diastolic function, and CIMT, but regain partially attenuates benefits.
- P<0.0001
- n=60
Why the study?
Obesity is associated with adverse cardiac and vascular structural and functional alterations, motivating evaluation of the effects of moderate weight reduction and subsequent partial weight regain on cardiovascular structure and function.
Does moderate diet-induced weight loss improve cardiovascular structure and function in obese adults?
Key Points
- To evaluate the effects of moderate diet-induced weight loss and subsequent partial weight regain on cardiovascular structure and function over a two-year period.
- Enrolled 60 obese adults (mean age: 46±10 years, body mass index: 37±3 kg/m2, 72% female) in a single-site, two-year dietary intervention evaluating low-carbohydrate and low-fat diets.
- Conducted cardiac and vascular ultrasound examinations at baseline and at 3, 6, 12, and 24 months after initiating the dietary intervention.
- Forty-seven subjects (78%) completed the two-year study, with average weight losses of 7.3±4.0% at 3 months, 9.2±5.6% at 6 months, 7.8±6.6% at 12 months, and 3.8±7.9% at 24 months.
- Age- and sex-adjusted mixed linear models revealed significant decreases over time in weight (p<0.0001), left ventricular mass (p=0.001), and carotid intima-media thickness (p<0.0001).
- Left ventricular diastolic function (E', p≤0.0001) and systolic function (S', p=0.001) improved significantly; partial weight regain attenuated peak improvements, but net benefits persisted at two years.
Study Design
Type
RCT (n=60)
Blinding
Single-blind (outcome assessor)
Randomization
Randomly assigned to low-fat vs. low-carbohydrate diet
Multicenter
No
Structured PICO
Does moderate diet-induced weight loss improve cardiovascular structure and function in obese adults?
P
Population
60 obese adults (mean age 46, 72% female) with class I or II obesity, free of type 2 diabetes, followed for 2 years to evaluate the cardiovascular effects of diet-induced weight loss.
I
Intervention
Reduced-calorie diet (low-fat or low-carbohydrate) for two years, supplemented with a daily multivitamin, comprehensive group behavioral treatment, and physical activity instructions.
C
Comparator
Low-fat diet vs. low-carbohydrate diet (groups were combined for primary analysis due to lack of significant differences in primary endpoints); comparisons were primarily made against baseline measurements.
O
Outcome
Changes in cardiovascular structure and function (LV mass, LV diastolic and systolic function, and carotid intima-media thickness) at 3, 6, 12, and 24 months.surrogate
Main Result
p-value: p=<0.0001
Limitations
- Small sample size with 78% completion rate at 2 years
- Single-site study
- Lack of a structured, monitored exercise program means increased physical activity could have contributed to the observed effects
- Requires further investigation to determine if structural improvements translate into improved clinical outcomes
- A structured, monitored exercise program was not part of the study, making it possible that increased physical activity contributed to the beneficial effects observed.
Key expert perspectives
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“Losing 20 or so pounds might seem daunting to some people, but we showed that even a more modest weight loss can yield heart and vascular benefits. It's important to realize that you can choose goals that are attainable and work progressively toward them. You don't necessarily need to lose 50 pounds to improve your heart function.”
Implication
Moderate diet-induced weight loss in obese adults is associated with significant improvements in cardiovascular structure and function, though partial weight regain diminishes these maximal benefits.
Abstract
Objectives The objective of this prospective, single-site, two-year dietary intervention study was to evaluate the effects of moderate weight reduction and subsequent partial weight regain on cardiovascular structure and function. Background Obesity is associated with adverse cardiac and vascular structural and functional alterations. Methods Sixty obese subjects (age: 46±10 years, body mass index: 37±3 kg/m2) were evaluated during their participation in a weight loss study. Cardiac and vascular ultrasound studies were performed at baseline and at 3, 6, 12, and 24 months after start of intervention. Results Forty-seven subjects (78%) completed the entire two-year follow-up. Average weight loss was 7.3±4.0, 9.2±5.6, 7.8±6.6 and 3.8±7.9% at 3, 6, 12, and 24 months, respectively. Age- and sex- adjusted mixed linear models revealed that the follow-up time was significantly associated with decreases in weight (p<0.0001), left ventricular (LV) mass (p=0.001), and carotid intima-media thickness (p<0.0001); there was also significant improvement in LV diastolic (E’, p≤0.0001) and systolic (S’, p=.001) function. Partial weight regain diminished the maximal observed beneficial effects of weight loss, however cardiovascular parameters measured at two years still showed a net benefit compared with baseline. Conclusions Diet-induced moderate weight loss in obese subjects is associated with beneficial changes in cardiovascular structure and function. Subsequent weight regain is associated with partial loss of these beneficial effects.
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Cite This Study
Fuentes et al. (2009) conducted an RCT in Obesity (Class I and II) (n=60). Diet-induced moderate weight loss vs. Baseline was evaluated on Changes in left ventricular (LV) mass and carotid intima-media thickness (CIMT) (p=<0.0001). Diet-induced moderate weight loss significantly improved left ventricular mass, diastolic function, and carotid intima-media thickness, though subsequent weight regain partially diminished these benefits.