I know how calories work, you count them and thats what you eat right? What if I ate something that stayed within my calorie limits, but has quite a bit of fat in? Does it matter?

Personally I don't count the fat, just the calories.
BUT I don't make it a habit to eat high-fat stuff all the time just 'cos it fits into my daily calorie amount...
Hope that makes sense.

Calorie composition does matter, but it seems that how much can vary a lot between individuals. Some people lose about the same amount of weight on 1500 calories, no matter where the calories come from. Other people find that it matters, not only in how they feel, but in how they lose.

I've found that I can eat about 300 to 500 more calories when eating low-carb to lose the same amount of weight when I eat high-carb. Fat doesn't seem to be as important as carbs. I believe I'm more sensitive to carbs than I was when I was younger, so I think people can be sensitive to different things.

A food journal will help you determine what you find most successful.

Initially, because I found that I was less hungry on low-carb, I assumed that I was losing more weight only because I was eating less as a result. It wasn't until I compared my weight loss on 1800 calories of high-carb eating to 1800 calories of low-carb eating that I found that even calorie-for-calorie, I lost more wieght on low-carb (even when taking into account that the first week or so is mostly water weight).

I'm not trying to push low-carb. I'm not convinced that everyone has to reduce carbs or reduce them to the same degree. Regardless of the plan you find most helpful, the food journal helps you see what is helpful and what is not. The hard part is journaling when you've eaten off-plan. It's so tempting not to document the off-plan foods, but it's really important if you want to see patterns that can help you fine tune your plan.

I actually try eat high fat foods, because when I'm calorie restricting I have a really hard time getting in enough fat - I really don't function well if I don't get enough. Alas, I have developed an allergy to my favorite high fat, healthy food - avocados.

Eclipse: Way sorry to hear about your avocado allergy. It always annoys me a little when people ask how I can enjoy them so much.

I feel better with more fat too. I always prefer to have the more natural product I can get so I use real organic butter instead of a substitute, mayonnaise instead of miracle whip, whole organic free range eggs instead of Egg Beaters - that sort of thing. If I stick to these whole foods I lose weight even with the fat. When I let in the junk...I gain (and obvious I do that often).

Fat keeps your mind off of food with how filling it is. Protein and fat together and I forget about food for many, many hours.

I wish I could go back to the moment they decided to convince us fat was bad for us (I'm not talking about transfat) and thrash the leader of the charge. lol

I make it a point to eat at least 20-30 grams of fat a day because the brain needs fat . I find calories coming from protein most filling though, so I don't go out of my eat to eat fatty. When I feel like I want to feel really full I eat a fried steak.

Everything you eat is either a carb, fat, or protein, or some combination of these things. These are called macronutrients. 1 gram of fat has 9 calories, 1 gram of carb or protein has 4 calories.

For a normal average diet the percentages of macronutrients are 50% carb, 25% fat, 25% protein.

A "diet plan" adjusts the macronutrient percentages. For example, on a very low carb diet like Atkins, the percentages are 10% carbs, 45% fat, 45% protein. Or on a low fat diet like Eat More Weigh Less, the percentages are 60% carbs, 15% fat, 25% protein.

Balancing your macronutrients is the key to balanced healthy eating, but that balance looks different for everyone. This is why not every diet works for everyone. You have to learn how your body responds to food.