Effect of high- and low-fiber diets on plasma lipids and insulin

Am J Clin Nutr. 1979 Jul;32(7):1486-91. doi: 10.1093/ajcn/32.7.1486.


Seven healthy young adults were maintained for two separate 1-week periods on each of two very high-carbohydrate diets, one with low-fiber and one with high-fiber content. In both diets 15% of the calories were from protein, 15% from fat, and 70% were from carbohydrate. The low-fiber diet consisted of milk, glucose, and dextrins in liquid formula form, the high-fiber diet was composed of starchy foods. The crude fiber content of the high- and low-fiber diets was 18.0 and 1.0 g, respectively. The diets were isocaloric and the subjects maintained a stable weight. During the low-fiber diet the fasting triglycerides rose, reaching a peak 45% above base-line in 6 days. During the high-fiber diet the triglycerides fell to a level slightly below base-line. The cholesterol fell 16 and 23% below base-line on the low- and high-fiber diets. The glucose response to test meals representative of each diet was similar. The insulin response to a low-fiber meal was twice as great as that to a high-fiber meal containing an equivalent amount of carbohydrate. The results suggest that carbohydrate-induced hyperlipemia does not occur if the high carbohydrate diet is rich in dietary fiber, and furthermore that the insulin-stimulating potential of foods in a very high-carbohydrate diet is a critical determinant of the magnitude of carbohydrate-induced lipemia.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Blood Glucose / metabolism
  • Cellulose / administration & dosage*
  • Cholesterol / blood
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / adverse effects
  • Dietary Fiber / administration & dosage*
  • Dietary Fiber / therapeutic use
  • Fatty Acids, Nonesterified / blood
  • Female
  • Glucose Tolerance Test
  • Humans
  • Hyperinsulinism / chemically induced
  • Hyperlipidemias / chemically induced
  • Insulin / blood*
  • Lipids / blood*
  • Male
  • Triglycerides / blood


  • Blood Glucose
  • Dietary Carbohydrates
  • Dietary Fiber
  • Fatty Acids, Nonesterified
  • Insulin
  • Lipids
  • Triglycerides
  • Cellulose
  • Cholesterol