PROBLEM TO BE SOLVED: To provide a modifier for an in vivo fatty acid composition for increasing the content of in vivo polyunsaturated fatty acid and modifying an in vivo fatty acid composition.SOLUTION: A modifier for an in vivo fatty acid composition comprises Camellia sinensis extract of less than 1 mass% as an active ingredient, or comprises Camellia sinensis catechin of less than 0.8 mass% as an active ingredient.SELECTED DRAWING: None【課題】生体内の高度不飽和脂肪酸の含有量を増加し生体内の脂肪酸組成を改変する、生体内脂肪酸組成の改変剤を提供する。【解決手段】茶（Camelliasinensis）抽出物を有効成分として１質量％未満、又は茶カテキンを有効成分として０．８質量％未満含有する、生体内脂肪酸組成の改変剤。【選択図】なし
