The present invention describes methods and compositions for the treatment of neurodegenerative conditions including Alzheimer's disease (AD) and aging. The present invention discloses an anaplerotic diet therapy for the treatment of AD. The high fat, low carbohydrate diet described in the various embodiments of the present invention increasing circulating ketone bodies, reduces amyloid-β (Aβ) deposition in AD patients, thereby improving cognition and locomotive skills.本發明係關於一種用於治療包括阿茲海默症(Alzheimer's disease,AD)及老化之神經退化性病症的方法及組合物。本發明揭示一種用於治療AD之補缺(anaplerotic)膳食療法。於本發明多項實施例中所闡述之高脂、低碳水化合物膳食可增加AD患者之循環酮體、減少類澱粉肽-β(Aβ)沉積,藉此改善認知及運動技能。