**Core Concept**
Atheromatous changes of blood vessels refer to the development of atherosclerosis, a condition characterized by the buildup of plaque in the arterial walls. This process involves the accumulation of lipids, inflammatory cells, and fibrous elements, leading to thickening and hardening of the arterial walls.

**Why the Correct Answer is Right**
Atheromatous changes of blood vessels primarily affect the middle-aged and elderly population. The process of atherosclerosis starts early in life, but it becomes clinically significant in individuals with risk factors such as hypertension, hyperlipidemia, and smoking. The endothelium plays a crucial role in the early stages of atherosclerosis, where it becomes dysfunctional, leading to the release of pro-inflammatory cytokines and the recruitment of inflammatory cells.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as atheromatous changes of blood vessels do not primarily affect children.
**Option B:** This option is incorrect as atheromatous changes of blood vessels are not limited to the elderly population, but rather become clinically significant in this age group.
**Option C:** This option is incorrect as atheromatous changes of blood vessels are not a result of poor nutrition.

**Clinical Pearl / High-Yield Fact**
Atheromatous changes of blood vessels are a major risk factor for cardiovascular disease, which is the leading cause of mortality worldwide.

**Correct Answer:** D.