Originally Answered: How many people who aren't actually obese lose weight permanently?
First, a direct answer to your question. Anyone can get to THEIR OWN PERSONAL ideal weight and stay there. I was very specific. A personal ideal weight is a percentage of body fat that cannot be judged remotely or on paper. And more, even being at ideal weight does not say fit and healthy even excluding diseases, because an ideal weight may be excess fat still.
Now, if starting obese, getting to a healthy weight range is easier. A body stores both fat and glycogen (body starch). The glycogen holds a lot of water, and fat holds some. More obese typically includes more body starch, and the water/glycogen is less calories per pound. Also, from the excess eating and wrong foods point of view, it is easier to get to a proper diet and get to a healthy weight with it. But, once at that BMI of 25, a healthy weight, what is left is fat, and that is 3,500 calories per pound, and from a total build, exercise is essential to reach that body shape goal which overrides the scale numbers. There are athletes of great body form in both sexes that the scale has a high weight. Weight alone does not clearly say totally ideal.
Will get to the point. Stand tall, pinch at belly height at your sides. Less than an inch is healthy. 1/2 to 3/4 is around ideal. We are most healthy with a little body fat to store fat soluble vitamins and provide sustained energy. Anyone with diet and exercise can get there. Without exercise diet needs to be so careful it is hard to maintain, because that glycogen and water comes back easily.
In terms of an "unhealthy" meal such as that trip to iHop with all the fixin's, one meal is not going to make much of a difference. 1000 calories is 1/3 to 1/2 pound and also is only half a day's energy.
In terms of 5 pounds, body weight varies in a day by food in your digestive tract (end-to-end) and water hydration. Overnight you lose weight in both metabolism and water in perspiration and respiration. It is not about an exact weight in this either then.
Temporary diet plans whether ketogenics of ultra-low carb like Atkin's, or glycemic of the South Beach Diet work for overweight somewhere into a healthy range. You then need a healthy diet maintenance and an exercise level for overall fitness and weight. So as I wandered a bit in information, I hope I was clear enough to state this:
Once close to ideal weight, by however path was achieved, but still 5 to 10 pounds over ideal, but in that healthy weight, you can get to the ideal weight and hold it by maintaining a healthy diet, that would allow for occasional treats of that unhealthy meal or dessert with no issue. It has to include an exercise plan that burns off the water/glycogen that forms in that treat. The people that get to this state have resolved they will have a healthy diet and exercise. There are some people with high natural metabolisms that have it easier, but for others it takes always watching the overall picture. Our general lifestyle today is far more sedentary than years ago. We sit at desks, watch TV, go to a market instead of growing food and raising animals to eat, play low energy games with our recreation time, have everything prepared in markets as frozen and a plethora of fast food restaurants. It is so easy to buy fat and sugar filled food. All this makes it hard to get to fitness.
Conclusion: A trip or two a month to iHop or McDonald's or the bakery is not going to make a difference. It is your standard eating and dietary patterns and your activity and exercise pattern that will determine your fitness. If you don't put in the effort, be satisfied and happy the way you are at any body shape/weight/fitness level and that's absolutely OK. Just be honest about it. If you don't believe it, your mom and everyone else won't believe it either. Or, put in the effort. It isn't easy to be and stay fit. Just don't play two sides of the fence like a lot of people do. They complain or are unhappy about their weight or fitness, and either do nothing about it, or chase easy ways that don't work.
In this long answer, I hope I got my point across. I meandered a bit.
Here is an answer that gets to great web sites and my guidance of a healthy diet.
The links have healthy eating as what and how to eat, ideal weight calculator from a very good source, nutrition lookup, articles and tips about weight loss,
a fitness web site http:www.livestrong.com/
and more. If you learned about food and fitness in what could take a couple of hours, you would see it is quite possible to correct any mistakes you are making and get to a perfect weight.
Did you know Diet Coke can make you fat even with zero calories?
(phosphoric acid, metabolism affect, potential insulin affect, psychological affect)