Walnut Oil Consumption May Counter the Damage Caused by Weight Gain

Updated: Oct 14, 2020

Polyunsaturated fats, such as those found in walnut oil, can improve blood cholesterol profile and counteract some of the negative effects of weight gain.
General Information
  • 15 Oct 2014
  • Sweden
  • Uppsala University
  • Riserus, E. et al
  • Double blind, randomized clinical trial
  • 39 adults
  • 7 weeks

A recent study conducted at Uppsala University in Sweden, led by Ulf Risérus and David Iggman, has recently added more fuel to the already highly-questioned link between fat consumption, body fat storage, and general health, which is turning out to be significantly less direct than traditionally thought.

The Study

The research team evaluated a group of 39 healthy, lean adults with an average age of 27. The study was a seven-week, double blind, parallel-group, randomized controlled trial. The two groups were fed muffins with 51% of energy from fat and 44% of energy from refined carbohydrates that added 750 calories to their usual daily diets. The muffins contained the same ingredients, except for the fats used. One set of muffins used vegetable oils with a larger share of polyunsaturated fatty acids, and the others were made with palm oil, known to contain almost exclusively saturated fatty acids.

The Results

Weight gain was recorded in both groups, but the group that consumed the muffins with polyunsaturated fatty acids experienced decreases in serum cholesterol levels. The polyunsaturated fats showed lipid-lowering effects, which can help promote weight loss further down the road. This study showed that polyunsaturated fats can improve blood lipid profile and counteract some of the negative cardiometabolic effects caused by considerable weight gain.

What Does This Mean?

Despite the traditional belief that all fats are equally bad for health, it seems that eating enough polyunsaturated fatty acids is even more beneficial than simply lowering overall fat intake. Polyunsaturated fats, from walnuts or sunflower oil, may provide protection against cardiovascular disease, but it is still questionable whether they directly affect weight loss. This study also dispels many of the myths that automatically associate excess weight with poor health, since there are many indicators to take into account.


  • Journal of the American Heart Association, Role of Dietary Fats in Modulating Cardiometabolic Risk During Moderate Weight Gain: A Randomized Double-Blind Overfeeding Trial (LIPOGAIN Study), 2014