Predictive factors of fat-free mass loss in obese patients after weight loss interventions

Sana Khamassi; Fatma Boukhayatia; Haifa Abdesselem; Emna Bornaz; Kamilia Ounaissa; Sana Hammami; Houda Bouhajja; Amel Gammoudi; Awatef Kacem; Emna Talbi; Jamoussi Henda; Chiraz Amrouche

doi:10.1530/endoabs.110.EP860

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Endocrine Abstracts (2025) 110 EP860 | DOI: 10.1530/endoabs.110.EP860

ECEESPE2025 ePoster Presentations Metabolism, Nutrition and Obesity (164 abstracts)

Predictive factors of fat-free mass loss in obese patients after weight loss interventions

Sana Khamassi ¹ , Fatma Boukhayatia ¹ , Haifa Abdesselem ¹ , Emna Bornaz ¹ , Kamilia Ounaissa ¹ , Sana Hammami ² , Houda Bouhajja ³ , Amel Gammoudi ⁴ , Awatef Kacem ⁴ , Emna Talbi ³ , Jamoussi Henda ⁴ & Chiraz Amrouche ¹

Author affiliations

¹National Institute of Nutrition and Food Technology, Department of Nutritional Diseases D, Tunis, Tunisia; ²National Institute of Nutrition and Food Technology, Clinical Biology Laboratory, Tunis, Tunisia; ³National Institute of Nutrition and Food Technology, UR17SP01-Clinical Biology Laboratory, Tunis, Tunisia; ⁴National Institute of Nutrition and Food Technology, Obesity Reserach Unit, Tunis, Tunisia

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Background: Muscle loss, particularly in the context of obesity, is a significant concern due to its association with various health complications, including insulin resistance, impaired mobility, and an increased risk of chronic diseases [1]. The aim of our study was to evaluate fat free mass loss in obese patients after weight loss intervention and to identify its predictive factors.

Methods: We conducted a prospective study of 100 obese adult patients over 6 months. Body composition was analyzed at baseline and at 6-month follow-up. Gait speed over 4 meters assessed physical performance. Sarcopenic obesity (SO) was defined in accordance with the 2022 EASO-ESPEN consensus statement. A balanced hypocaloric diet was prescribed and patients received regular follow-ups. A significant loss of fat-free mass (FFM) was defined as a reduction of more than 5% in FFM.

Results: The mean age was 44.42±13.25 years and the sex ratio (M/F) was 0.11. At baseline, the mean BMI was 40.07±5.77 kg/m². About 20% of the participants had a below-average fat-free mass index of 20.34±2.53 kg/m², and 19% were identified as having SO. At 6 months, 78 patients completed the study. The average weight loss and the average FFM loss were 4.13±6.98% and 0.42±5.63%, respectively. Significant loss of FFM was identified in 11% of patients after weight loss intervention. The level of physical activity was comparable between patients with significant FFM loss and those without (P = 0.42). Significant FFM loss was associated with a higher prevalence of binge eating disorder (62.5% vs 18.5%;P = 0.014) and prediabetes (75% vs 36.9%;P = 0.039) at baseline. However, sarcopenic obesity and functional impairment were not significantly associated with FFM loss (P = 0.14 and P = 1.0, respectively). Dietary survey revealed that significant loss of FFM was associated deficiency in vitamin B9 intake (87.5% vs 36.9%;P = 0.009), and deficiency in vitamin C intake (87.5% vs 27.5%;P = 0.002) at baseline. However, total caloric intake as well as protein intake were comparable (P = 0.15 and P = 0.07, respectively). Furthermore, FFM loss was negatively correlated with vitamin B6 intake (r=-0.24;P = 0.04) and vitamin B9 intake (r=-0.41;P = 0.041). Multivariate analysis identified prediabetes, vitamin B9 deficiency, and binge eating disorder syndrome as independent factors associated with significant FFM loss (P = 0.045;OR=7.48, P = 0.012;OR=23.43, P = 0.018;OR=10.93, respectively).

Conclusion: Our study highlights the importance of targeted nutritional and behavioral interventions to mitigate muscle loss in obese patients and enhance overall health outcomes in this population.

References: 1. Wannamethee SG, Atkins JL. Muscle loss and obesity: the health implications of sarcopenia and sarcopenic obesity. Proc. Nutr. Soc. 2015;74:405-12.