The term "you are what you eat" is cliché and not very descriptive, but it's true. Let’s put some credence to that statement now. Starting out seems daunting, many people choose long term goals and they fail quickly, within weeks, because they don't also create reachable, short term goals that can help keep you focused. My first bit of advice is create 2 sets of goals; a long term goal, and multiple, short term waypoint goals that you can use to keep you on track. Make sure these are reasonable, attainable goals as well. Having a goal of your "high school weight" if you're 40 years old and have had children is probably not that reasonable. There are plenty of weight/height/age/sex charts that give you a range weight goal, this is what I would recommend. I also recommend having a long term goal weight RANGE instead of weight number. Having a single number can become obsessive to people, being 1 pound from your goal is not a failure unless you let it be.
On to your nutrition. I'm what most nutrition experts would consider a "generalist". I don't believe in restrictive or "crash" diet types. Any diet that eliminates or severely restricts either calorie amounts or types of macronutrients (macronutrients are the 3 main calorie types, I.E. carbohydrates, fats, proteins). While there are perfectly valid reasons for low carb or high protein diets, they aren't easy plans to follow, and require a lot of extra willpower to be successful with, and they won't help you lose weight any faster in the long term. LET ME RESAY THIS SO YOU UNDERSTAND. Macronutrient restrictive diets WILL NOT help you lose weight any faster. Also, diets like Atkins, or South Beach or Paleo diet are difficult under any circumstance, and even more so under social situations, beside the very strict adherence required, for them to be effective long term, they need to be a life choice (I.E. for the rest of your life), so if you aren't ready to make that kind of commitment, I would reconsider them.
For most people, I recommend just following the USDA food pyramid (www.pyramid.gov). While I don't follow every tenant that they print to the letter, for most people, their percentages, amounts, and food types are close enough to keep you healthy and happy for a long long time.
So how do we begin? First, do a little research, figure out what a complex carbohydrate is, what lean protein means, and what healthy fats are. These are vital. Know that you need lots and lots of vegetables (learn to like them folks, there are plenty of choices, don't give me the "I don't like veggies" speech, I've heard it before, you need em, supplements won't cut it.). Understand that cheese sauces and cream sauces, white flour, white sugar, High Fructose Corn Syrup (HFCS), hydrogenated oils, and saturated fats are all not good things to have in large quantities. Fill your day's diet with veggies, berries (the best fruits are generally berries), whole grains, whole grain rice, beans, nuts, lean meats (including red meats in limited quantity, lower fat volumes are better with these), healthy fats (Extra virgin olive oil, coconut oil, some sunflower oil...etc.), fish (white fish, not shell fish usually).
Some of you may be thinking that this is a huge change. You'd be surprised at how easy it is to make most of the things you enjoy with these better ingredients. It just takes a modicum of effort. And a desire to treat your body right and live a healthy, long life.
As to losing fat. Generally the food choices I talk about above are a great start, and they'll give your body all the tools it needs to be chemically and hormonally happy. But unless you figure out how many calories you need daily, this won't help you lose fat. To do this you need to limit your calories. This may seem difficult, but it's generally not as hard as it seems. There are online diet tabulators (some pay, some free) that you can use, or if you don't like that, you can keep a journal, there are even IPhone and Android apps you can use. What you really want to change for LIFE is eat a moderate deficit for your situation, and monitor your food choices. I can talk individually to anyone who really wants to dig into how much their deficit should be, but generally, the more obese you are, the bigger the deficit can reasonably be (within reason here folks). This is especially true of body fat percentage. I don't recommend a "crash" diet with an extreme calorie deficit simply because it's unsustainable, and the ultimate goal is teaching your body, slowly, how to live off the correct number of calories, not how to quickly drop fat, and then be confused about calories once you reach your goal. What I try to do is take it slow with people, allow them to form good habits, which allow them to continue being health for life, I will slowly reduce their deficit over months or even years in extreme cases, until when they reach the goal weight (and fat %) they want, the change to eating maintenance calories is minimal, and easy to keep up with and with no change to the type of food they eat, there's really very little or no transition period to maintenance.
FYI, for those of you with small children. Don't use them as an excuse. I've heard "my child will not eat
A few notes on this topic.
-Recently I've heard a few folks tell me that they "can keep eating what I'm eating and just exercise more". Nope, sorry, you can't. That's not going to cut it. Food is vital. You can fool yourself all you want, it won't make it right.
-Doctors, personal trainers, and nutritionists are NOT the experts in this field. You want nutrition advice? Go see a registered dietitian. Doctors generally receive minimal training in this field, nutritionists have no standard to conform to, they may be great, they may be awful. Registered dietitians are required to pass certain, state wide requirements, so at least you know they meet minimum standards.
-You don't need to be super super restrictive for this to work. As long as you're honest and don't beat yourself up over your calories, going over or eating something "bad" every couple of weeks isn't the end of the road. It's only a failure if you let it stop you from continuing.
-Find a support network; whether that is a friend, neighbor, family member(s), an online group, or something else. You probably need to rely on someone else for support every once and a while. There's no need to be a "tough guy", sometimes we slip up, and having someone there for support is a good thing.