Updated: Oct 21, 2021
At the end of the day, too many calories in vs. out will prevent you from losing weight regardless of the macronutrient make up of your eating habits. With calories in check, it is useful to understand what fat does when it enters the body, particularly with how it helps shed pounds as some dietary fats help you tap into stored fat more than others. Here's a quick rundown on some good fat sources and why they are great at assisting you in your body composition goals.
Good vs Bad
As saturated fats generally raise LDL (bad cholesterol) levels and increase the risk of heart disease, "good fats" (unsaturated) help curb appetite, seem to alter the gene expression regulating fatty acid oxidation in adipose tissue, enhance metabolism, and secrete hormones necessary for proper bodily function (1)(2). Healthy fats are comprised of Omega-3's; Fat found in fish, nuts and seeds, and Omega-6's; Commonly found in certain oils that remain liquid at room temperature. Another type of triglyceride (fat) you may have heard of, found in palm oil, coconut oil, breast milk, and cow butter, is MCTs (Medium Chain Triglycerides) This fat molecule is the exception to the otherwise problematic saturated fat in that they have a different chemical structure and can be more easily digested.
Why Are Good Fats Good?
These fat acids increase metabolic rates and enhances the bodies response to leptin. Leptin is a regulatory protein hormone made in and released by fat cells that stimulates the sensation of satiety. Leptin tells you when you are no longer hungry, essentially curbing your appetite when levels reach a certain point. When leptin signals the brain to suppress appetite, your metabolic rate further increases by enhancing thyroid production output. The more fat cells on your body, the more leptin your body produces. The issue is that your body stops responding to leptin as good as it used to and instead, builds a resistance to it which typically results in overeating (3).
MCT's have a variety of healthy properties but in the context of fat loss, it can help suppress appetite, induce thermogenesis (raising body temperature resulting in burning calories), and are slightly lower in calories (by around 10%) that other fats. Simply switching to MCT oil (coconut oil) when cooking can improve weight loss results compared to using olive oil (4).
How To Use Good Fats as Part of a Weight Loss Program
To put this information into practical use, it is recommended to have good sources of fat make up 15-30% of your total caloric intake. When done properly (eating fish, nuts, and seeds), incorporating fats in your diet can prevent you from overeating, while providing you with energy, especially when carbohydrate stores are depleted. So instead of drastically lowering your calories in order to burn fat for fuel, eat as many calories as possible while still losing weight by creating balanced meals high in protein, high in low-glycemic carbs (low in sugar), and nutrient dense, Omega-3 and Omega-6 rich foods to alter your metabolic demands. This, along with a substantial exercise routine, will greatly enhance your chances of altering your body composition in your favor and for the long term.