Whenever you do something different, people like to pass judgement and throw resistance in your path. It's annoying. I'm very familiar with it. Fortunately, you can score a win with people during times of expected change (marriage, death, graduation, new house, etc.)
Although full of nonsense, The New Year is a pretty standard time of expected change.
See, what usually happens when you try to change is that people will work to hold you back, even if they don't do so intentionally. This is something you should expect. The resistance to a new you is baked into society. Maybe we're just more comfortable that way. But the reason doesn't matter. Just be thankful that we have New Year's. Because during January and a few weeks in February, you can try out just about ANYTHING and get away with it. Here's an example:
Them: "What the hell are you doing?"
You: "Just trying out [insert weirdo-level action] for the New Year. Gotta change it up!"
Them: "Oh...uh...I see...well good luck with that!"
Or something similar. People will just assume that you'll just go back to being whatever they thought you were like before, so they won't give you too much flack for trying something different. But if you were to do something new and random with no holiday or occasion attached, you'd get complaints, unfounded concerns, and all manner of resistance.
There are even people that sound like they're on your side, but may not understand your attempt at true evolution. They'll actually end up sabotaging you by being friendly. For example, your favorite donut-buddy might say "Oh, you're working out for the New Year? Keep it up!" Once a week goes by, they'll offer you some fresh and creamy donuts because "you deserve it". Don't fall for that. It's a trap.
In fact, you should be working to associate your eating with people that despise donuts. Your donut-buddy might be a little upset at your choices early on, but if you're real about it, you should both go on with a happy co-existence.
Finally, when you actually end up changing for the better along the way, naysaysers won't really have too much to say about your upgrade. Since you'll have wrapped your change around a holiday or an event, they won't get too upset. The change will make sense in their heads, even if it doesn't make logical sense. People just need a 'why'.
Person 1: "Joey stopped eating at Taco Bell."
Person 2: "Really? Why?"
Person 1: "Dunno, but he stopped after he left that last job."
Person 2: "Ohhh...I think it's because they served tacos at work once."
Person 2 really has no clue, but will make up some bullshit rationalization about the job and Taco Bell. That's okay though. That's Person 2's problem.
You've made the change, and the people around you are going to go along with it. They've made up reasons in their head for it all to make sense. As long as you have a 'why' attached to it. The New Years is a great one.
Try making a change when your birthday comes around, when an election happens, when you have a child, when you relocate, when you join a group, when you change jobs, etc. You can add symbolism too. Get a haircut, buy new shirts, shop at different stores, rearrange your home, etc. And don't get too worried about what people think, at the very least, they'll think you're interesting while you're trying things out.
But times are changing, and so should you.
Happy New Year's everyone!