True.
I guess I was trying to address the idea that some people have that the weight is instantly regained. While that's common it's only because people go right back to eating like they were previously. While metabolism slows a little because your body is carrying less weight (this happens no matter how you lose weight), 'starvation mode' isn't something that happens to anyone with more than 5-10% body fat. Above that, muscle wasting won't happen if you're getting enough protein. It doesn't hang on to fat when it stored it precisely to use as an energy source when food is scarce. This kind of thing is just the kind of nonsense supplement companies selling protein shakes came up with and it's been repeated so much that everyone thinks it's the truth.
To be fair, ~95% of all 'diets' (whether that's an actual plan like Atkins or just reducing calories and eating healthy) 'fail' because changing habits is damn hard.
And I wanto to reiterate that from a long term perspective a more moderate eating plan is definitely better. Even Lyle McDonald (mentioned in my previous post) advises a more moderate approach in his own 'crash diet' book.
You bring up another important point and that is muscle wasting. A very common misconception is that cardio is the only effective exercise for weightloss which is very much not the case. I think adding some resistance training (free weights, circuit, bands, whatever) is extremely important if you are trying to lose weight.
When you lift weights you are damaging muscle fibers which the body then needs to rebuild, that is what makes the muscle stronger. Well, not only do you burn calories when you are physically doing the work of lifting weights but that rebuilding is extremely calorie intensive. Cardio will give you more bang for the buck while you are actually doing the running, jogging, biking, swimming, or whatever but you stop burning calories much closer to when you stop as opposed to resistance training where you will burn calories for hours after you put down that last weight or get off of that last machine.
This highlights another falsehood many dieters believe, and that is that the scale is the great arbiter of success. Muscle weighs more than fat so building muscle while you are losing fat might make the scale move more slowly in the down direction but that really doesn't matter, you are still losing fat which is ultimately the goal. Turning 5 pounds of fat into 5 pounds of muscle will not only make you generally smaller but will also increase you basal metabolic rate which is the number of calories you consume just existing.
When I or the experts talk about a lifestyle change sometimes that is overly vague. What I and most of them mean is that your new lifestyle will include the following (as mine does now):
Doing some form of exercise every day or just about every day. This could mean a nightly walk/jog/run, biking someplace instead of taking the car, joining a gym, or hitting the community pool. Ideally you will do a couple of these on alternating days.
Scrutinizing the menu at a restaurant and going with a healthier choice the majority of the time even if something less healthy looks better.
Cooking more and making processed food less.
Changing how you shop. Maybe you buy fresh food every other day instead of packaged food twice a month.
Reading labels. This can't be stressed enough. It will make you notice portion size (something often overlooked) and see what you are putting in your body. If you don't recognize something in the ingredient list chances are you don't want it in your body.
Doing small things like parking further away or taking the stairs instead of the elevator.
Altering your leisuretime activities. Maybe not reading for 3 hours a day but reading for 2 hours and walking or hiking for 1.
My favorite, doing more and watching less. Instead of watching tennis on TV for example grab a friend and go play tennis.
Hopefully this is helpful information.