In a world of fad diets and new low carb, low cal, low fat products appearing on grocery shelves daily I thought I would shed some insight into what is going into your body… and you thought you were making the right choice.
While at UBC, I have been fortunate enough to take classes in the Food Science faculty, learning about nutrition, food chemistry, processing, engineering and biochemical nature of foods. Through studying fat-free products I came across some information about a few products that many people use without even knowing it!
There are three different types of fat substitutes that are commonly used. The first being, a protein based substitute deriving from soy, milk/whey, or egg whites, which are partially coagulated by heat to create a ‘fat type’ smoothness. Containing only 1.3 calories/g due to their broken up particle nature, they are used to create fat free products such as ice creams, yogurts, cheese, salad dressings, mayonnaise, soups and sauces. The trade-mark name for this is Simplesse although I doubt you will ever find this written on a label, rather you will see “egg and milk protein”, “whey protein concentrate” or the best… “modified milk ingredients”.
The second type of fat substitute is derived from carbohydrate sources, corn, potatoes, wheat, and tapioca. From these sources the cellulose, starch, gums and maltodextrins are removed and used to create the ‘mouth feel’ flavor that fats possess. The trademark name for this type of substitute is Maltrin, which is fully digestible and contains 4 cal/g, compared to the usual 9 cal/g in fats. Other carb-based fat replacers available range from non-digestible to partially digestible therefore ranging from 0-2 cal/g, examples being Avicel or Betatrim. You will find carb based fat substitutes in margarine, salad dressings, frozen desserts, frostings and processed meats.
Now for the real zinger! A fat based, fat substitute. Sounds too good to be true.. right? WRONG! Trademarked as Olean, or Olestra, this product was approved in the USA in 1996, and has yet to be approved in Canada for many good reasons. Olestra is a sucrose polyester fat based substitute.
Here is a little chemistry for you. Fat are typically made from triglycerides which contain three glycerols and a fatty acid. The glycerol molecules are three carbons, 3 hydroxyl groups; while the fatty acids are long hydrocarbon chains with carboxylic acid and methyl groups held together by ester bonds. Anyways, in Olestra instead of 3 fatty acid chains attached to glycerol, there are 6-8 fatty acid chains attached to a sucrose (sugar) molecule. Therefore there is no longer the glycerol component essential to what a fat is. Still following?
Olestra mimics a saturated fatty acid (BAD FATS!), therefore it is commonly used in products that would used saturated fats, such as those which are fried, while also giving the rich and creamy texture that ordinary fats have… except with zero calories due to the chemical make-up. Again, sounds too good to be true doesn’t it? Well here is when I break the bad news. Olestra is not broken down by the body. Enzymes (proteins used to breakdown foods) act in a similar way to a lock and key. You cannot break down a food (lock) unless you have the correct enzyme (key). Regular fats are broken down by the enzyme lipase, but because Olestra doesn’t have glycerol and contains sucrose, lipase cannot break it down. Instead it passes through our bodies un-metabolized and not absorbed, thus having a 0 calorie effect.
So guess what this means… Olestra acts as a laxative! In large quantities it causes abdominal cramping and changes in stools. Also it removes the content value of the foods consumed with Olestra. Fat-soluble vitamins are not absorbed by the digestive tract, thus companies which used Olestra have to add vitamin A, D, E, K to make their products have some nutritional value. This is what the FDA doesn’t tell you…
When Olestra was first on the market, products which used it had to state the consequences of consuming it. Citing right on the package, “May cause cramps, diarrhoea” or the best, “May cause anal leakage” (no joke, check out a fat free Pringles container from 1997). Why don’t you see this anymore? Olestra makers won a court judgement in which they argued that fibre supplements did not have to state these details so why did they. So while many Americans and now Canadians too, think they are making the healthy decision by eating fat free products, every time they are really consuming a synthetic laxative!
My point being people, read your labels and be careful when consuming any processed product! Fat free is not necessarily a good thing!
