Effects of Underfeeding and Overfeeding on Growth and Multi-Organ Metabolic Alterations in Wistar Rats

Background: Early-life nutritional imbalance is increasingly recognized as a key determinant of long-term cardiometabolic health. Both undernutrition and overnutrition during critical developmental periods can induce persistent alterations in growth, adiposity, endocrine regulation, and organ function, predisposing individuals to metabolic disorders later in life.

Objective: This study evaluated the long-term metabolic consequences of early-life nutritional imbalance in Wistar rats by comparing growth patterns, organ morphometry, metabolic biomarkers, and cardiometabolic risk indices following underfeeding and overfeeding.

Methods: A controlled experimental study was conducted using male Wistar rats randomly assigned to three groups: underfed, normal-fed, and overfed. Somatic growth parameters (weight, height, length, and circumference gain) were monitored. After the experimental period, major organs were harvested for morphometric analysis. Serum biochemical markers including liver and renal function indices, glucose, lipid profile, inflammatory markers, and oxidative stress indicators were measured. Cardiometabolic risk indices such as the atherogenic index of plasma, Castelli risk indices, and TG/HDL ratio were calculated. Data were analyzed using one-way ANOVA and multiple regression.

Results: Overfeeding significantly increased weight gain and promoted multi-organ hypertrophy, particularly in the liver, heart, spleen, kidneys, and brain, whereas underfeeding restricted somatic growth and reduced organ weights. Underfed animals exhibited lower glucose, triglycerides, cholesterol, inflammatory markers, and oxidative stress, alongside higher HDL and antioxidant activity. Regression analyses revealed that organ morphometry strongly predicted lipid-related cardiometabolic indices.

Conclusion: Early-life nutritional imbalance significantly alters growth, organ development, and cardiometabolic risk profiles. Organ morphometric changes appear closely linked to metabolic regulation and may serve as potential indicators of cardiometabolic risk.