During a low-energy diet phase, individuals who are metabolically unhealthy overweight/obese (MUO) experience greater improvements in certain cardiometabolic risk factors, but their improvements during long-term lifestyle intervention are not as significant as individuals with metabolically healthy obesity (MHO), according to a study published in the International Journal of Obesity.
Researchers conducted a post-hoc analysis of the PREVIEW study (ClinicalTrials.gov Identifier: NCT01777893), which was a multicenter, 2-by-2 factorial, randomized controlled trial for diabetes prevention to compare type 2 diabetes incidence and changes in body weight and cardiometabolic risk factors between participants with baseline MHO and MUO. The study was conducted between June 2013 and March 2018. Eligible participants were aged 25 to 70 years and were overweight or obesity and had prediabetes. The study consisted of an 8-week low-energy diet-induced weight loss phase followed by a 148-week lifestyle-based weight maintenance phase.
A total of 2165 participants began the low-energy diet phase. Of these, 1012 were MHO, and 1153 were MUO at baseline. During the low-energy diet phase, MHO and MUO participants lost 10.5% of their body weight. After the study, those with MHO maintained a weight loss of 2.7%, while those with MUO maintained a weight loss of 3.0%. Over 156 weeks, participants with MHO had a greater reduction in waist circumference and regained more fat-free mass than those with MUO.
Participants with MUO showed greater or similar benefits in almost all cardiometabolic risk factors during the low-energy diet, particularly in triglycerides and HDL cholesterol (with differences of 3%-7% from baseline values compared with MHO). However, the benefits in cardiometabolic risk factors for those with MUO disappeared during the first year of the weight-maintenance intervention. On the other hand, participants with MHO experienced greater improvements in cardiometabolic risk factors in the long-term, especially in 2-hour plasma glucose, the homeostasis model for assessment of insulin resistance, and triglycerides (with differences of 4%-7% from baseline values compared with MUO).
After losing an average of 10.5% of body weight on a low-energy diet, 60% of initially MUO participants became MHO. However, only 38% of those who converted could maintain their status despite an average sustained weight loss of 4.3%.
The study is limited by its exploratory nature and a high percentage of missing data.
“…after adjustment for confounding factors, compared with those with baseline MHO, individuals with baseline MUO had greater improvements in cardiometabolic risk factors during the low-energy diet phase, but had smaller improvements during the 3-year lifestyle intervention, despite similar weight change between the two obesity phenotypes throughout the study,” the study authors wrote. “Participants with MUO had higher 3-year cumulative type 2 diabetes incidence than those with MHO.”
Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Zhu R, Huttunen-Lenz M, Stratton G, et al. Associations of obesity phenotypes with weight change, cardiometabolic benefits, and type 2 diabetes incidence during a lifestyle intervention: results from the PREVIEW study. Int J Obes (Lond). Published online July 7, 2023. doi:10.1038/s41366-023-01328-y