Long-term effects of a low carbohydrate, low fat or high unsaturated fat diet compared to a no-intervention control

Nutr Metab Cardiovasc Dis. 2010 Oct;20(8):599-607. doi: 10.1016/j.numecd.2009.05.003. Epub 2009 Aug 19.


Background and aim: Very low carbohydrate ad libitum diets have been shown to enhance weight loss without increasing cardiometabolic risk factors but no kilojoule-controlled trials have been conducted relative to no intervention. The aim of this study was to compare the changes in weight and other cardiovascular risk factors in 3 isocaloric energy-restricted diets to no-intervention control after 1 year.

Methods and results: One hundred and thirteen subjects (age 47 ± 10 years, BMI 32 ± 6 kg/m(2) with one additional cardiovascular risk factor) were randomly allocated to one of three isocaloric diets (VLC-very low carbohydrate, 60% fat, 4% carbohydrate, n=30; VLF-very low fat, 10% fat, n = 30; HUF-high unsaturated fat, 30% fat, n = 30) with intensive support for 3 months followed by minimal support for 12 months compared to a control group (no intervention, n = 23). The estimated weight change was -3.0 ± 0.2 kg for VLC, -2.0 ± 0.1 kg for VLF, -3.7 ± 0.01 kg for HUF and 0.8 ± 0.5 kg for controls (P=0.065). After correcting for baseline values, decreases in body weight and diastolic blood pressure in the diet groups (-2.9 ± 5.2) were significantly different to the increase in the control group (0.8 ± 5.0) (P<0.05). No differences in cardiovascular risk factors were observed between the diet groups.

Conclusion: Significant cardiometabolic risk factor reduction was observed equally with VLC, VLF and HUF diets after 15 months, compared to an exacerbation of risk factors in the control group. At a modest level of adherence, 3 months of intensive support on these dietary patterns confer an improvement in cardiometabolic profile compared to no dietary intervention after 15 months.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / analysis
  • Blood Pressure
  • Body Composition
  • Body Weight
  • Cardiovascular Diseases / etiology
  • Cholesterol, LDL / blood
  • Diet, Carbohydrate-Restricted*
  • Diet, Fat-Restricted*
  • Dietary Fats, Unsaturated / administration & dosage*
  • Female
  • Humans
  • Insulin / blood
  • Male
  • Middle Aged
  • Risk Factors


  • Blood Glucose
  • Cholesterol, LDL
  • Dietary Fats, Unsaturated
  • Insulin