Lipid levels of expeditioners in Antarctica: response to a reduced-fat, oleic acid and carbohydrate-enriched diet.

The study examined the effects of a reduced-fat, oleic acid and carbohydrate-enriched diet on serum lipid profiles and body weight in the setting of an isolated Australian Antarctic station. A 12-week dietary intervention period was provided for 30 healthy, free-living expeditioners against a background diet typical of the Australian population. The diet tested a "modified U.S. Dietary Goals" regimen which increased oleic acid preferentially (29% energy from fat and 46% from carbohydrate, polyunsaturated: monounsaturated: saturated fatty acid ratio [P:M:S] of 0.6:1.3:1.0, 30 g fibre/day, less than 300 mg cholesterol/day). During the intervention period, mean serum HDL-cholesterol (HDL-C) levels remained relatively stable while mean serum total cholesterol (TC) fell significantly (a fall of 0.95 mmol/l, p < 0.05). The mean serum triglyceride (TG) level rose initially (1.44 to 1.64 mmol/l, p < 0.05) but the level returned to baseline (1.41 mmol/l) by the end of the intervention period. The change in TG level was associated with increased dietary carbohydrate but not with changes in body weight, alcohol intake or season. The study demonstrates that a reduced-fat, oleic acid and carbohydrate-enriched diet can result in significant improvements in serum lipid profiles. The diet was acceptable to the subjects and was easily provided in Antarctica with unobtrusive changes to the typical Australian diet.