>>Father+(OP)
You're in the faux enlightenment that everybody gets during weight loss. Everybody I've ever known losing weight starts discovering the wonders of healthy eating and nutrition as they lose weight, vowing never again to go back to their old habits. Then they slip further down the line and 1-2 years they're back to their original weight, plus some.
Weight loss isn't the challenge. Maintaining it for the rest of your life is.