IN the fifty years since Higgins1 obtained evidence that fructose has a greater tendency to change into fat in the body than has dextrose, more evidence has accumulated, much of it in the past few years, to show that lipid metabolism in man and experimental animals is affected differently by different carbohydrates2–5. Recently, it was found that substitution of sucrose for starch in the diet of weanling and three month old rats caused metabolic changes6, and that diets containing sucrose, and more especially fructose, increased plasma cholesterol levels and carcass and liver fat of adult rats compared with diets containing dextrose or liquid glucose or a standard laboratory diet7.