One must make a huge distinction between the appearance of health and the actual state of health. Too often, we become blinded to the true nature of illness and dis-ease, by the outward illusion of health. I was most recently thinking of this dilemma in regards to weight loss. The epidemic of eating disorders and diet mania is a prime example. Individuals starve themselves, deprive the body of essential nutrients, and generally spiral out of control toward an ever widening state of illness, under the guise of creating heath by being skinny. It is a sham. Health is independent of weight, and it is more important to live a healthy life at any weight than it is to be at the bottom of the BMI.
I do not mean to imply that we should be skinny or fat, that one is good while the other is bad. It is just as likely the case that a 220 lb woman is as healthy as a 150 lb counterpart. I have worked with patients that are "rail thin" with chronic aches and pains, and triglycerides and cholesterol off the charts. We can not, nor should we judge a book by its cover.
It is true that when we begin to move towards a more ideal state of health, we will often loose excess weight. This is an expected result and if the lifestyle changes are permanent, the weight loss should be too. So begin your journey to find the balance of health, internal and external, and enjoy a more complete way of living.