With few exceptions, every naturally occurring food item contains either fat or carbs, but usually not both. Indeed they are our bodies two sources of energy, with unused energy from both sources being stored in your body as fat.
Since they both are stored as fat, let's think about them as equivalents for a brief moment. Even in a healthy diet, it's not uncommon to eat a large serving of potatoes, rice, or bread, all of which are made basically of carbohydrates. You wouldn't (I hope) sit down and eat that equivalent amount of butter, oil, or cream. So your diet likely already has far more carbs than fat.
Then looking at refined carbs (ones that lack fiber), and especially sugar, they spike your insulin leading to more fat cell creation and can promote the process that leads to cardio vascular disease.
To be clear, not all fats are created equal, and I've outlined the six types of fat in the table below so you know which to avoid like the plague. But in my own experience I’ve found that making an effort to avoid sugar and other refined carbs, will do more for your fat loss goals than avoiding actual dietary fat. Indeed, many fat free foods have only replaced fat with sugar so that it still tastes good enough to eat. For example, Snackwells has 2g of fat removed, but 13g of carbs (including 4g of sugar) were added to make sure it remains a tasty treat.
If you follow our overarching philosophy of doing your best to eat real food, you will get your fair share of fat, and that’s not necessarily a bad thing.
Atherosclerosis: Hardening of the arteries
The Different Types of Fat in Order of Declining Nutritional Value:
Omega-3 Fatty Acids
Source: Wild fish, flaxseed oil
Effects: Anti-inflammatory, lowers serum triglycerides, repairs membranes
Source: Olive and canola oil
Effects: Stimulates liver metabolism, reduces atherogenesis
Source: Vegetable oils, nuts, avocados
Effects: Anti-inflammatory, but in excess amounts can cause immune dysfunction
Saturated fatty acids
Sources: Grass-fed animal meats, milk and dairy products
Effects: Atherogenic in a specific genetic background; raises levels of type A LDL very high (the less harmful cholesterol type)
Sources: Palm oil, coconut oil, palm kernel oil
Effects: Energy source, some suggestion of stimulation of atherosclerosis
Omega-6 Fatty Acids
Sources: Farm raised animals and fish fed on corn and soy
Effects: Atherosclerosis, insulin resistance, immune dysfunction, pro-inflammatory
Trans fats (partially hydrogenated oils)
Sources: Synthetic, found in processed foods only
Effects: Atherosclerosis, nonalcoholic fatty liver disease
Lustig, Dr. Robert. Fat Chance. Penguin Publishing Group, 2012.
Astrup et al., "The Role of Reducing Intakes of Saturated Fat in the Prevention of Cardiovascular Disease: Where Does the Evidence Stand in 2010?" Am. J. Clin. Nut. 93 (2011)
P.w. Siri-Tarino et al., "Saturated Fat, Carbohydrate, and Cardiovascular Disease," Am. J. Clin. Nutr. 91 (2010).