You eat too much

There are two approaches to the eating out problem, and you can use both at various times depending. First, don't eat out frequently unless you can be certain what you're eating is very healthy and or calorie controlled. Second, treat eating out as an exception, do it once a week, and eat almost whatever you want. And have fun with it that way. It's not terribly hard to ballpark that eating out meal on calories within a few hundred, and so long as you're not talking about consuming 1,500+ calories in a meal, the deficit you run the rest of the week can easily more than make up for it.

It takes a net deficit of about 3500 calories to lose one pound of fat (it's not exact, but it's a close proximity). All calories aren't created equal, so I'm assuming we're not talking about living on Dairy Queen blizzards here.

So once you find your equilibrium line on how many calories you can consume for your lifestyle and general metabolism, just removing 500 junk calories per day, will probably see you shed dozens of pounds in a year (if you're, say 50 or 60 pounds overweight). This wouldn't even require exercise, the calorie deficit would drop the weight; any exercise would just make it easier, and boost your ability to burn while resting.

If you often eat at a cafeteria at work, as another example, or anywhere on a routine, you can likely find out specific calorie numbers for the things they make there. And when all else fails, lots of foods are predictable on their ballpark calorie numbers (eg a salad, chicken sandwich, slice of pizza, slice of cheesecake, etc).

I really hated the calorie counting. It felt like a chore to me, but I was a bit surprised by my weight gain, and didn't think I was eating that much. I was 155 pounds at 25 years old circa 2005 (naturally skinny), and gradually added 40 pounds of fat over the next 8 years as my metabolism slowed with age. I simply couldn't burn off calories as quickly at rest.

My biggest advice on diet, regarding accuracy, is to use calorie counting solely to identify how great your over-consumption is or is not, and what the prime culprits are. Once you do that, throw them out of your diet, at least until you gain control over your calorie intake without having to think about it. The odds are, it's just two or three repeating things causing the problem (eg drinking 3 sodas a day, or eating two pizzas a week). For me, instead of particularly calorie dense take-out or frozen pizza, every two or three weeks I'll make a thin crust whole wheat pizza at home; satisfies my craving for pizza, and I can control exactly what it consists of.

Accuracy is very important when you're first taking an accounting of your intake. You need to know what the exact problems are, and how many calories you may be over-consuming. Eat your regular diet, and measure it before you make changes. Once you acquire confident control over your diet and calorie intake - it becomes pretty automated with practice - get rid of the calorie counting, it's a torturous chore and is unnecessary after you change your lifestyle / diet.

With a few specific changes, you'll find it's actually very hard to put on weight. It's my opinion that the health / diet / fitness industries scare a lot of people away by making things overly complex. It's really simple:

1) Identify and measure the calorie intake and discover what your biggest couple problem children are (whether it's eating out, soda, candy, ice cream, pasta, pizza etc)

2) Throw those things out, they're probably 3/4 of the problem. Replace them with low calorie, higher protein foods that will be filling. Do not throw out all of your diet, that's not necessary, will make changing much harder, and you can make subtle adjustments as you go along.

3) Keep counting calories until you have a new lifestyle in place and can put it all on automation, anywhere from a few weeks to a few months should do it

4) Swap in low or zero calorie, zero sugar items where you can. Even if you just use this as a stop-gap, it helps a ton. And gradually reduce snacks and candy intake, if that's a problem. Get sweets back to being a rare treat, rather than a constant thing. Zero sugar, low calorie candies; diet soda; zero sugar jello; zero sugar ice cream; high cocoa dark chocolate; you get the idea.

I found there are an amazing number of options for replacement foods these days. eg:

http://www.amazon.com/Explore-Asian-Organic-Spaghetti-7-05-O...

Black bean spaghetti in place of traditional pasta. It's not bad, and it's very high in protein.

I occasionally snack on ostrich jerky, called Ostrim (protos-inc.com). 80 calories, it's a significant piece of jerky, and it has 14g of protein. I snack on skim milk string cheese, 50 calories, 7g of protein. I swapped out really shitty breakfast foods for greek yogurt, and I hate most greek yogurt but I found one I really like the taste of that has a reasonable 7g of sugar (yoplait vanilla, 100 calories, 13g of protein); some greek yogurts are like candy bars these days with sugar. I eat almonds every day as a snack, and replaced peanut butter with almond butter (still high'ish in calories so I use less of it, but it's much healthier).

5) Boost protein intake reasonably. It can be as simple as eating some extra tuna or salmon, black beans, or egg beaters. I don't like protein shakes for example, so I find my protein intake in food. Lift some weights to add muscle, even on a very limited basis. This will not only meaningfully reduce your risk of diabetes, but the muscle you add will do a lot of work for you. Cardio is fine of course too if that's your thing. The muscle you add will act as a shield against your ability to gain weight again.