Dietary fish as a major component of a weight-loss diet: effect on serum lipids, glucose, and insulin metabolism in overweight hypertensive subjects

Am J Clin Nutr. 1999 Nov;70(5):817-25. doi: 10.1093/ajcn/70.5.817.


Background: Obesity in hypertensive patients is associated with dyslipidemia and insulin resistance, both of which are improved by weight control. n-3 Fatty acids have diverse effects on mechanisms underlying atherosclerosis, including a decrease in serum triacylglycerols and an increase in HDL(2) cholesterol.

Objective: The objective was to examine whether dietary fish enhances the effects of weight loss on serum lipids, glucose, and insulin in 69 overweight, treated hypertensive patients.

Design: Overweight patients being treated for hypertension were randomly assigned to either a daily fish meal (3.65 g n-3 fatty acids), a weight-loss regimen, the 2 regimens combined, or a control group for 16 wk.

Results: Sixty-three subjects completed the study. Weight decreased by a mean (+/-SEM) of 5.6 +/- 0.8 kg with energy restriction. Weight loss decreased fasting insulin (P = 0.003) and the area under the curve for insulin (P = 0.003) and glucose (P = 0.047) during an oral-glucose-tolerance test. The greatest decrease occurred in the fish + weight-loss group. There was no independent effect of fish on glucose or insulin. Fish increased HDL(2) cholesterol (P = 0.004) and decreased HDL(3) cholesterol (P = 0.026) without altering total, LDL, or HDL cholesterol. Weight loss had no effect on these variables. Fasting triacylglycerols fell significantly with fish consumption (29%) and weight loss (26%). The fish + weight-loss group showed the greatest improvement in lipids: triacylglycerols decreased by 38% (P < 0.001) and HDL(2) cholesterol increased by 24% (P = 0.04) compared with the control group.

Conclusions: Incorporating a daily fish meal into a weight-loss regimen was more effective than either measure alone at improving glucose-insulin metabolism and dyslipidemia. Cardiovascular risk is likely to be substantially reduced in overweight hypertensive patients with a weight-loss program incorporating fish meals rich in n-3 fatty acids.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Animals
  • Antihypertensive Agents / therapeutic use
  • Blood Glucose / metabolism
  • Diet, Reducing*
  • Energy Intake
  • Fatty Acids, Omega-3 / administration & dosage*
  • Female
  • Fishes*
  • Humans
  • Hypertension / complications*
  • Hypertension / drug therapy
  • Hypertension / metabolism
  • Insulin / metabolism
  • Lipids / blood
  • Male
  • Middle Aged
  • Obesity / complications
  • Obesity / diet therapy*
  • Obesity / metabolism
  • Postmenopause
  • Weight Loss


  • Antihypertensive Agents
  • Blood Glucose
  • Fatty Acids, Omega-3
  • Insulin
  • Lipids