First off, we need fat to survive. It’s one of the macronutrients along with protein and carbohydrate. How much depends on your lifestyle, but about according to the Mayo Clinic, about 20-35% of your daily caloric intake should be fat. Approximately between 40-78 g/day with less than 22g being saturated fat. I tablespoon of peanut butter has about 8 g of fat, a tablespoon of olive oil, 14g. So the normal daily intake is actually quite reasonable, (if you are not eating the Standard American Diet and lots of deep fried things).
Fat became vilified in the 60′s and 70′s when a link was found between dietary fat, heart disease and weight gain, so the knee jerk reaction was to reduce ALL dietary fat. The mantra became fat = bad, carb = good. We now know that it’s much more complicated than that. We don’t need large amounts of fat, but we definitely need it for healthy skin, hair, hormones, cell membranes, and many other things.
So what is a Low-Fat food anyway? “Low-Fat” foods have been processed and modified to chemically or physically remove naturally occurring lipids. High in energy, fat also tastes good. It dissolves a lot of flavor molecules, so things that have large amounts of fat tend to make taste buds happy. If you take fat out of a food, you have to add something back in so that it’s palatable; sugar and artificial flavors., The mantra became fat = bad, carb = good. Perceived caloric deficit of low-fat food was met with a frenzied no-holds-barred increase in overall food intake, so instead of losing weight, US’ers gained weight, died of heart disease more than ever, and also more diabetic. Whoops.
Processing of foods creates fats that can cause inflammation in our systems: trans-fats, elevated omega 6′s (very readable article here) which manifest in atherosclerosis and obesity. The final most recent outcome is that low-fat has been shown to be low-health. Reasonable amounts of fat from real food (nuts, seeds, avocados, fish, plant oils) is part of a healthy food paradigm. As usual, the solution is not rocket science, it won’t sell tons of books, nor is it a magic bullet diet or pill answer. Eat reasonable amounts of real food. You knew it all along.