title: Effect of dietary fatty acid composition on substrate utilization and body weight maintenance in humans.
abstract: OBJECTIVE
  Dietary fat content is a primary factor associated with the increase in global obesity rates. There is a delay in achieving fat balance following exposure to a high-fat (HF) diet (≥ 40% of total energy from fat) and fat balance is closely linked to energy balance. Exercise has been shown to improve this rate of adaptation to a HF diet. Recently, however, the role of dietary fatty acid composition on energy and macronutrient balance has come into question.
  
  
  METHODS
  We chose studies that compared monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and saturated fatty acids (SFA). We have reviewed studies that measured diet-induced thermogenesis (DIT), energy expenditure (EE), or fat oxidation (FOx) in response to a HF meal challenge, or long-term dietary intervention comparing these fatty acids.
  
  
  RESULTS
  While single-meal studies show that SFA induce lower DIT and FOx compared to unsaturated fats, the effect of the degree of unsaturation (MUFA vs. PUFA) appears to yet be determined. Long-term dietary interventions also support the notion that unsaturated fats induce greater EE, DIT, and/or FOx versus SFA and that a high MUFA diet induces more weight loss compared to a high SFA diet. Sex and BMI status also affect the metabolic responses to different fatty acids; however, more research in these areas is warranted.
  
  
  CONCLUSIONS
  SFA are likely more obesigenic than MUFA, and PUFA. The unsaturated fats appear to be more metabolically beneficial, specifically MUFA ≥ PUFA > SFA, as evidenced by the higher DIT and FOx following HF meals or diets.
authors.affiliation: Department of Nutrition, Hospitality, and Retailing, Texas Tech University, PO Box 41240, Lubbock, TX, 79409, USA, sridevi.krishnan@ttu.edu.
authors.forename: Sridevi
authors.initials: S
authors.lastname: Krishnan
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Cooper
mesh_terms: D000222:Adaptation, Physiological; D059305:Diet, High-Fat / Q000009:adverse effects*; D004041:Dietary Fats / Q000009:adverse effects* / Q000378:metabolism; D004734:Energy Metabolism; D015444:Exercise; D005227:Fatty Acids / Q000009:adverse effects* / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000009:adverse effects / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000009:adverse effects / Q000378:metabolism; D006801:Humans; D009765:Obesity / Q000209:etiology* / Q000378:metabolism; D050177:Overweight / Q000209:etiology* / Q000378:metabolism; D010084:Oxidation-Reduction; D022722:Thermogenesis; D015430:Weight Gain
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated