A PUFA-rich diet improves fat oxidation following saturated fat-rich meal

Eur J Nutr. 2017 Aug;56(5):1845-1857. doi: 10.1007/s00394-016-1226-9. Epub 2016 May 18.

Abstract

Purpose: To determine substrate oxidation responses to saturated fatty acid (SFA)-rich meals before and after a 7-day polyunsaturated fatty acid (PUFA)-rich diet versus control diet.

Methods: Twenty-six, normal-weight, adults were randomly assigned to either PUFA or control diet. Following a 3-day lead-in diet, participants completed the pre-diet visit where anthropometrics and resting metabolic rate (RMR) were measured, and two SFA-rich HF meals (breakfast and lunch) were consumed. Indirect calorimetry was used to determine fat oxidation (Fox) and energy expenditure (EE) for 4 h after each meal. Participants then consumed a PUFA-rich diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 21 % of total energy was PUFA) or control diet (50 % carbohydrate, 15 % protein, 35 % fat, of which 7 % of total energy was PUFA) for the next 7 days. Following the 7-day diet, participants completed the post-diet visit.

Results: From pre- to post-PUFA-rich diet, there was no change in RMR (16.3 ± 0.8 vs. 16.4 ± 0.8 kcal/20 min) or in incremental area under the curve for EE (118.9 ± 20.6-126.9 ± 14.1 kcal/8h, ns). Fasting respiratory exchange ratio increased from pre- to post-PUFA-rich diet only (0.83 ± 0.1-0.86 ± 0.1, p < 0.05). The postprandial change in Fox increased from pre- to post-visit in PUFA-rich diet (0.03 ± 0.1-0.23 ± 0.1 g/15 min for cumulative Fox; p < 0.05), whereas controls showed no change.

Conclusions: Adopting a PUFA-rich diet initiates greater fat oxidation after eating occasional high SFA meals compared to a control diet, an effect achieved in 7 days.

Keywords: High fat; Metabolism; Polyunsaturated fatty acid; Saturated fatty acid.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Basal Metabolism
  • Body Mass Index
  • Calorimetry, Indirect
  • Cholesterol / blood
  • Diet
  • Dietary Carbohydrates / administration & dosage
  • Dietary Fats / administration & dosage
  • Dietary Proteins / administration & dosage
  • Energy Metabolism
  • Fasting
  • Fatty Acids / administration & dosage*
  • Fatty Acids, Unsaturated / administration & dosage*
  • Female
  • Humans
  • Lipid Metabolism*
  • Male
  • Meals
  • Nutrition Assessment
  • Oxidation-Reduction
  • Single-Blind Method
  • Triglycerides / blood
  • Young Adult

Substances

  • Dietary Carbohydrates
  • Dietary Fats
  • Dietary Proteins
  • Fatty Acids
  • Fatty Acids, Unsaturated
  • Triglycerides
  • Cholesterol