Fat is an edible substance that plays many roles in food and cooking.
In cooking, it can bind ingredients together, it can act as a heat-transfer medium, it can prevent sticking, it can convey and enhance flavour, and it can provide texture and mouthfeel in the finished product.
In terms of nutrition, it is one of the three macronutrients in our food (the other two being protein and carbohydrates), providing energy and acting as a carrier for vital micronutrients.
Throughout most of culinary history, getting enough edible fat was a constant challenge. It’s only in the 20th century that the problem became having too much.
We like fat in everything we eat, but not in ourselves. We like to feel thin — but we don’t like our meals to.
The function of fat in food
Fat provides mouth feel and acts as a carrier for tastes and nutrients. Without it, what we are eating feels dry in the mouth, or thin and unsatisfying, as though you haven’t just finished swallowing something. Sometimes the word is even used to describe how filling a wine feels in the mouth.
Fats naturally present in flour are necessary to help the gluten be elastic and hold the carbon dioxide produced by the yeast. Adding a small amount of additional fat can in some instances increase the volume of a loaf of bread by up to 20%. But most of the increase comes with the very first amount of the added fat: so it’s not worth going crazy adding more because you won’t see a proportional increase in volume. Adding some kind of fat to a bread also helps the bread keep longer, because the fat coats the starch molecules and helps them keep moisture in longer.
Fat makes pastry tender because it coats the gluten in the dough, so that the gluten strands can’t adhere well to each other, which would make a “tough” crust.
Nutrition
All edible fats have 9 calories per gram of fat (120 calories per tablespoon).
Some fat in the diet is absolutely essential to the body. Without it, the body can’t absorb certain fat-soluble vitamins such as A, D, E and K.
The current thinking is that the worst fat of all is not saturated fat, or an animal fat, but rather man-made trans-fats.
The real kicker is when you remember all the fuss about how bad butter was for you because it was animal fat. Food writers everywhere duly parroted and trumpeted the news, causing many people to switch to margarine for health reasons as urged to by doctors, scientists, food writers and all the health industry. Oops. Turned out that margarine as made at the time was just about the worst thing you could do for your body: it was bursting with trans-fats from making the oils solid at room temperature. Those who had given up their beloved butter must have been very cross indeed. Those who continued frying in bacon fat and butter while being lectured by people who fried in margarine must have had a hard time suppressing their smiles.
Literature & Lore
An ad that ran in many American newspapers in September 1947 said:
“Yes, used fats are still needed, says Clementine Paddleford, Food Editor of This Week. Here’s the answer to you women who’re wondering if you should still save used fats! Secretary of Agriculture Clinton P. Anderson says, “It is still necessary to conserve every pound of fat, since the over-all fat supply situation is little better now than it was last year.” You see, many things we use require industrial fats or their products, and there aren’t enough fats in the world to go around, as yet. So every pound we women of America can save will help. Please… keep up the good work until we’ve got this situation really licked. Keep turning in your used fats. — American Fat Salvage Committee, Inc
“And ye shall eat the fat of the land.” Genesis 45:18.
Sources
Sygo, Jennifer. It’s high time to end the war on dietary fats. Montreal, Canada: Montreal Gazette. 29 June 2011.