Semantics: Life long diets and ever-changing lifestyles

A pet peave for many of us.  What does Semantics even mean?  According to Dictionary.com:


the meaning, or an interpretation of the meaning, of a word, sign, sentence, etc.: Let's not argue about semantics.

No, Dictionary.com, let's argue about it...  I was reading a friend's status online regarding a change in diet.  Another person commented that diets don't work, it has to be a lifestyle change; completely discrediting my friend's efforts.

WTF, right?
Let's think about this:
  Humans are (for the most part) omnivorous; our diet consists of a variety of plants and animals.
People who are overweight go on diets to lose weight, but when the diet is over, the weight comes back(more on this in a moment).

Bear with me, now, I'm getting to the meat of it all.  No need to go nuts.  The fruit of the matter is this: Diet refers to what we eat.  We have a diet our entire lives, for the purpose of staying alive. Diets DO WORK, otherwise we'd all be dead.

Now we are at the main course of my concern: I went to the Dr. a week or so ago and he said it's time to look into a low carb, high protein lifestyle.  He then says "Notice, I said lifestyle, not diet."  Oh Hell, it's spreading...

I kept my mouth shut because I really like my Dr.  Seriously, though, I was unnerved.  A diet lasts as long as you stick to it, and thus is not necessarily a temporary thing.  Diets work.  Quitting a successful diet when the weight is off doesn't.  A Lifestyle also changes, possibly with the tide for some people, and therefore is not any better or worse than a diet.  These days, people's lifestyles change with whatever fad is popular that week.

You with me so far, because now it's time for the bacon...

What's the common denominator, regardless of the word you use, that determines (mostly) the success of your efforts?  Maintain.  Maintain a healthy lifestyle/diet. 

Now I could go into a cornicopia of advise on how to eat right, live well, etc.  I would be an absolute hypocrite.  I know everything I need to get healthy.  Most of us do.  It is continuous effort that will make or break most of us. 

So when someone says they need to change their diet, know they are talking about their lifestyle.  When someone says it's time for a lifestyle change, know they also could be changing their diet (or exercising more, or quitting a bad habit).  Regardless, KNOW that the point is an effort to be well, and support that effort.  If you want to advise to Maintain that effort, by all means, do so, within the means of their efforts (certain things are meant to be temporary, and we're not physicians).  By no means do any of us have the authority in someone's life to just come out and say their efforts will not work, simply because of the words they use.  You are thus missing the entire point and should be kicked in the nuts.