Randomised trial · Obesity (Silver Spring, Md.) · 2016Conflicts declared

Canola oil, belly fat and heart risk factors

What it found

In a controlled feeding trial, diets high in monounsaturated fat from canola oil reduced android (belly) fat mass by about 3% compared with a flax/safflower oil diet.

The reduction was seen mainly in men and was linked to small improvements in blood pressure and triglycerides.

What they found

Studies in people

Belly fat reduction

After 4 weeks, the canola and high-oleic canola oil diets led to lower android fat mass (about 3.1 kg and 3.09 kg) compared with the flax/safflower oil diet (3.2 kg). The difference was small but statistically significant.

Effect in men

Men lost more android fat on the high-oleic canola oil diet compared with the flax/safflower oil diet. Women showed no differences across the five diets.

Blood pressure link

The drop in android fat mass was linked to small decreases in systolic and diastolic blood pressure after the canola and high-oleic canola oil diets.

Triglyceride link

The drop in android fat mass was also linked to a decrease in triglyceride levels after the high-oleic canola oil diet.

Body weight

Participants weighed slightly less at the end of the canola and high-oleic canola oil diets compared with the flax/safflower oil diet.

What the authors conclude

“Diets high in MUFA (compared with PUFA) reduced central obesity with an accompanying improvement in MetS risk factors.”
Liu X, Kris-Etherton PM, West SG, et al, 2016

Also in their conclusions

  • They conclude that diets high in monounsaturated fat, compared with polyunsaturated fat, reduced central obesity and improved metabolic syndrome risk factors.
  • They suggest that such diets may be beneficial for treating and perhaps preventing metabolic syndrome.
  • They note that the reduction in android fat mass was accompanied by favorable shifts in cardiometabolic risk factors.

How it was done

Abdominal obesity is a key feature of metabolic syndrome, which raises the risk of heart disease and type 2 diabetes. The authors wanted to see whether diets high in monounsaturated fats, like those from canola oil, could help reduce central obesity and related risk factors.

They ran a randomised crossover feeding trial with 101 adults who had central obesity and at least one other metabolic syndrome risk factor. Each person ate five different controlled diets for 4 weeks each, separated by 2 to 4 week breaks. The diets used different oils: regular canola, high-oleic canola, high-oleic canola with DHA, corn/safflower, and flax/safflower.

What it can’t tell you

  • The study lasted only 4 weeks per diet, so it cannot show what happens over the long term.
  • It cannot prove that increasing monounsaturated fat, rather than decreasing polyunsaturated fat, caused the improvements.
  • The results may not apply to people without central obesity or metabolic syndrome risk factors.

The paper

Title
Effects of canola and high-oleic-acid canola oils on abdominal fat mass in individuals with central obesity
Type
Randomised controlled trial
Evidence
Studies in people
Summarised from
Full text
Cite
Liu X, Kris-Etherton PM, West SG, et al (2016). Effects of canola and high-oleic-acid canola oils on abdominal fat mass in individuals with central obesity. Obesity (Silver Spring, Md.). doi:10.1002/oby.21584Free full textPubMed 27804268DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error