Most dieters spend hours counting calories and checking out food labels. Even though calories are important, they only play a small role in weight loss. The key to maintaining a healthy body weight is to find your ideal macronutrient ratio. This means your diet should provide optimum amounts of protein, fats, and carbs.

Contrary to popular belief, dietary fat is not your enemy. It can actually help you slim down and keep the pounds off. Just make sure you choose "good" fats, such as those found in avocado, olive oil, and fish.
The Truth about Fats
Fatty foods have been vilified for decades. Most dieters are still afraid to eat fats. The truth is that this nutrient plays a crucial role in health and well-being. It not only provides energy, but also insulates your organs, enhances vitamin absorption, and balances your hormones.

Along with protein and carbs, fat is a major source of fuel for your body. For this reason, it's called a "macronutrient." When you exercise or do physical work, your body burns glycogen (carbs) for energy. As soon as your liver and muscle glycogen stores are depleted, you start burning fat for fuel. In the absence of fat, the body will use protein to sustain itself. This leads to fatigue, catabolism, fractures, and loss of strength. A diet that’s rich in healthy fats helps spare protein and muscle tissue, especially when you cut back on carbs.

Dietary fat also prevents inflammation, maintains skin elasticity, and regulates your body's temperature. Some types of fat slow down aging and promote the formation of new cells. Others aid in blood clotting and support brain function. Certain fats, such as ALA (alpha-linolenic acid) and omega-3s, can not be produced in the body. For this reason, they must be obtained through diet or supplements.

The Role of Dietary Fat in Weight Loss
Countless studies indicate that that dietary fat aids in weight loss. This nutrient can help you maintain a normal weight and improve body composition. Heart-healthy fats, such as omega-3 and omaga-6, curb hunger, suppress cravings, and lower LDL (bad) cholesterol while increasing HDL (good) cholesterol levels. They also regulate satiety hormones and keep you full after a meal.

Dietary fat can help you lose weight in several ways. First of all, it spares lean muscle and prevents protein breakdown. Secondly, it suppresses your appetite and wards off hunger. Some studies suggest that a high fat intake can reduce sugar cravings. As a result, you will eat less and lower your total calorie intake.

High-fat diets also appear to have a positive impact on adipokines, the hormones produced by your fat cells. For example, adiponectin raises metabolism and increases fat breakdown. The more good fats you eat, the higher your levels of adiponectin. Dietary fat also supports testosterone production. Testosterone plays a vital role in metabolism, fat burning, and muscle growth. This is particularly important for men and regular gym goers. Adequate fat intake can help you build muscle faster, shed fat, and recover from exercise in less time.

However, keep in mind that not all fats are created equal. Doughnuts, fries, chips, margarine, corn oil, sauces, and junk food contain trans or hydrogenated fats, which affect your health and metabolism. These compounds are heavily processed, causing high cholesterol, hypertension, heart disease, obesity, and even cancer.
Monounsaturated and polyunsaturated fats should be a staple in your diet. These nutrients promote weight loss and improve your blood lipids. They are found in fatty fish, nuts, seeds, unrefined vegetable oils, and avocado. Saturated fats, which occur naturally in meat, eggs, and dairy, are beneficial too when consumed in moderation.

Summary 

• There are several types of fat available, including monounsaturated, polyunsaturated, saturated, and trans fats. 
• Hydrogenated or trans fats are considered unhealthy and may cause chronic diseases. 
• Monounsaturated and polyunsaturated fats fight inflammation, curb hunger, and delay aging.
• Saturated fats increase testosterone levels and regulate your hormones.
• Adequate fat intake can aid in weight loss and preserve muscle tissue.