Time to fatten up our diets.  Saturated and trans fat?  No.  But replacing carbohydrates with unsaturated fat could lead to longer, healthier life.
D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D002149:Energy Intake; D005224:Fats, Unsaturated / Q000008:administration & dosage* / Q000737:chemistry; D006304:Health Status; D006801:Humans; D008136:Longevity; D010938:Plant Oils / Q000008:administration & dosage / Q000737:chemistry; D044242:Trans Fatty Acids / Q000009:adverse effects / Q000737:chemistry
D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005224:Fats, Unsaturated; D010938:Plant Oils; D044242:Trans Fatty Acids