The skinny on fat
For years, we were told to decrease our intake of fat because fat increased cholesterol levels, which would increase the risk of a heart attack. As a result, we saw the boom of the “fat-free” movement, and fat-free products flooded the market shelves. People shunned ghee, butter, nuts and avocados because they were high-fat foods. But instead of lower rates of heart disease, we saw an increase in obesity, type 2 diabetes and heart disease. What happened? High-carbohydrate diets, especially carbohydrates from processed foods, cause an increase in insulin production that can lead to fat storage and inflammation. Population studies of people who consume higher-fat diets, such as the Mediterranean and France approaches to eating, as well as numerous tropical regions, have shown lower rates of heart disease, obesity and Alzheimer’s disease. These diets also are high in fruits and vegetables and have little-to-no processed food.
Why do we need fat? Fat is one of three macronutrients (protein and carbohydrates are the other two). All fat contains 9 calories per gram, making it very energy-dense. Fat has many important functions in the body, including:
- Hormone production – sex hormones, steroid, and cholesterol
- Brain function and mood
- Absorption of fat-soluble vitamins – vitamins A, D, E and K
- Flavor – fat carries flavor and provides mouth-feel that improves meal satisfaction
- Satiety – fat takes longer to digest than carbohydrates, so you feel fuller for longer
What are the different kinds of fat? Fat can be divided into different types based on their chemical structure. Most foods contain a combination of these different fats, with one being the predominant type.
1) Monounsaturated Fats (MUFA): Monounsaturated fats are liquid at room temperature and can hold up well under high temperatures. Found commonly in avocados, olive oil and almonds, MUFAs get a big “thumbs up,” as numerous studies have linked diets high in MUFAs with reduced risk of heart disease and diabetes.
2) Polyunsaturated Fats (PUFA): Also liquid at room temperature, PUFAs are a large category of fats that are better understood when further split into two groups: omega-3s and omega-6s. Omega-3 fats are known to be anti-inflammatory and associated with lower risk of heart disease, diabetes, depression and obesity. Foods rich in omega-3s include, mackerel, sardines, anchovies, chia seeds, flax and walnuts. Omega-6 fats are found widely in nut and seed oils and many processed foods commonly eaten in a Western diet. These fats can become pro-inflammatory when consumed in excess (as in a typical diet) and when omega-3 intake is low.
3) Saturated Fats: Saturated fats are solid at room temperature and stable at high temperatures. Found in foods such as butter and lard, saturated fats can raise LDL (“bad” cholesterol) but also raise HDL (“good” cholesterol). Once thought to be a major cause of increasing one’s risk for heart disease, saturated fats are now considered neutral in terms of their impact on health. Coconut oil, which is a saturated fat is favored for its heart and brain benefits.
5) Trans Fats: Most trans fats are artificially produced and can be identified on a food label by the words, “partially hydrogenated vegetable oil.” Trans fats are commonly found in processed foods because they can help extend the shelf life of food. These fats are the most dangerous to consume as they increase inflammation, cause multiple alterations in lipid levels, affect arterial function, increase insulin resistance and promote excess belly fat. There is no recommended level for trans fats and should be avoided.
How much fat to consume? Choosing high-quality fats is of primary importance and the total amount of fat you consume ultimately depends on your weight and health goals. Adding MUFAs, omega-3 PUFAs and/or coconut oil to every meal will ensure that you are getting enough of the right kinds of fat. Including fat at each meal will help you to feel fuller for longer, balance blood sugar level, and increase your satisfaction with each meal.