I'll dip my toes into this thread ...
I'm 41 years old, 175lbs. I'm stronger, more fit and am 'in better shape' now than when I raced mountain bike competitively, played rugby or football. I was always very active and fit .. then I got married, comfortable and gained a tonne of weight. Over the span of nine months I dropped 110lbs strictly counting calories and running .. it wasn't the best way to lose weight, it put me in a shitty head space when it came to food / eating .. but it was nice to get back to my 'fighting weight'. Soon after making that change, I started doing CrossFit and that tapped into my competitive side and I haven't stopped since. That was almost 6 years ago.
Nowadays, I do 'standard' CrossFit classes 5-6 days a week. I do focused Olympic Weightlifting 2-3 times a week. I do yoga and meditate. I run, swim and ride whenever the urge strikes me. I'm able play with my kids. I make sure I fuel my body well. Shortly after I began CrossFitting, I used myself as a bit of a guinea pig. I adopted a paleo inspired lifestyle in part to see if it could / would help me perform better in the gym (also I was simply curious). Now I believe in that ****. I emphasize whole foods, focusing on quality cuts of meat, lots of veggies and good fats, nuts seeds and some fruit. I ate strict paleo for about three years .. and slowly re-introduced certain foods .. and have taken a more 80 / 20 approach to my eating (so yes, I'll crush the occasional pizza, smokie or two at a game, a pint of ice cream and I drink craft beers). The most important thing, I believe in eating intuitively and allowing yourself to live life (there needs to be joy in what you do).
I'm also one who feels ketosis and ketogenic diets in general aren't sustainable. That's just me though and I'll never advocate against something that works for an individual .. listen to your body and do what feels right .. I just believe that carbs aren't evil .. they are necessary .. especially when you are pushing yourself hard. It's all the sugar that's in a standard North American diet that kills people. Eliminate processed food in your day to day and I guarantee you will see improvement (even without lifting a barbell).
Had to giggle in the Draft Thread .. I go through about three dozen eggs a week .. they are staples for me day to day.