Dietary modulation of body composition and insulin sensitivity during catch-up growth in rats: effects of oils rich in n-6 or n-3 PUFA

Br J Nutr. 2011 Jun 28;105(12):1750-63. doi: 10.1017/S0007114510005659. Epub 2011 Jan 31.


The present study investigates whether excessive fat accumulation and hyperinsulinaemia during catch-up growth on high-fat diets are altered by n-6 and n-3 PUFA derived from oils rich in either linoleic acid (LA), α-linolenic acid (ALA), arachidonic acid (AA) or DHA. It has been shown that, compared with food-restricted rats refed a high-fat (lard) diet low in PUFA, those refed isoenergetically on diets enriched in LA or ALA, independently of the n-6:n-3 ratio, show improved insulin sensitivity, lower fat mass and higher lean mass, the magnitude of which is related to the proportion of total PUFA precursors (LA+ALA) consumed. These relationships are best fitted by quadratic regression models (r2>0·8, P < 0·001), with threshold values for an impact on body composition corresponding to PUFA precursors contributing 25-30 % of energy intake. Isoenergetic refeeding on high-fat diets enriched in AA or DHA also led to improved body composition, with increases in lean mass as predicted by the quadratic model for PUFA precursors, but decreases in fat mass, which are disproportionately greater than predicted values; insulin sensitivity, however, was not improved. These findings pertaining to the impact of dietary intake of PUFA precursors (LA and ALA) and their elongated-desaturated products (AA and DHA), on body composition and insulin sensitivity, provide important insights into the search for diets aimed at counteracting the pathophysiological consequences of catch-up growth. In particular, diets enriched in essential fatty acids (LA and/or ALA) markedly improve insulin sensitivity and composition of weight regained, independently of the n-6:n-3 fatty acid ratio.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Arachidonic Acids / analysis
  • Arachidonic Acids / therapeutic use*
  • Body Composition / drug effects
  • Docosahexaenoic Acids / analysis
  • Docosahexaenoic Acids / therapeutic use*
  • Food, Fortified*
  • Glucose Tolerance Test
  • Insulin Resistance / physiology*
  • Linoleic Acid / analysis
  • Linoleic Acid / therapeutic use*
  • Malnutrition / diet therapy*
  • Rats
  • Rats, Sprague-Dawley
  • Refeeding Syndrome / diet therapy
  • Refeeding Syndrome / prevention & control
  • Regression Analysis
  • alpha-Linolenic Acid / analysis
  • alpha-Linolenic Acid / therapeutic use*


  • Arachidonic Acids
  • alpha-Linolenic Acid
  • Docosahexaenoic Acids
  • Linoleic Acid