Two things: people don't like to be told what to wear or what to eat.
Company dress codes are a good example of the first point. Dress codes do have their place, but when a small company tries to impose rules like they are a big company, people do not like it. Or if the code is out of touch with the actual work that is done, people become disgruntled.
For example, years ago I worked at a company that designed and produced phone books. It didn't pay much but I didn't mind working there. It was a good group of people to work with. Most hated the dress code, though. We were an art department that needed to dress up every day. Ties were not required but slacks, dress shoes, polos or collared shirts were required. No jeans or sneakers. As an art department we hated it.
The vice-president of personnel established a panel of people (the dress code police) to help decide what articles of clothing was appropriate and what wasn't. As you can guess they were not a very popular group in the company. Most of the panel were hand-picked and were the people wishing the code would be even stricter. Needless to say, the panel became the joke of the company and a strong attitude of "no one's going to tell me what to wear!" became the norm.
The second thing people don't like is to be told what to eat. "Eat your beans!" "Finish your vegetables! They are GOOD for you!" What's that you say? Your mom said these commands to you? How did I know? I'm psychic like Shawn Spencer.
As adults, people do not want to be told by anyone what they can eat -- including their doctor or mother. People want to eat what they want to eat and when they want to eat it.
So the lady in the Production Dept. in your company who scolds her co-workers for eating various types of food, isn't well liked because people don't want to be told what to eat.
It's not only in the workplace or at social gatherings that people scold others for what they eat. Oh no! Facebook has opened the door to allow people to post their diets and photos of all the healthy food they eat -- and, of course, what everyone else should be eating too!
So now I'll get to the point...
I discovered years ago when I was in high school that my classmates really didn't care what vitamins or minerals were in certain foods or which foods were best to consume after a sports practice. They also didn't care how many calories, carbs or fats are in particular foods. After a few comments that they didn't care, I took the hint and shut my mouth.
Those people are now adults and I can say confidently that they do not want someone scolding them like their mother about what they shouldn't eat. I've seen the "mothers" out there scolding adults and it is never received well.
Why is it then that fitness-oriented or recently-converted-health-nut people think they have to fill their Facebook timelines and albums with photos of what they eat everyday? Or let people know they are working hard to achieve their fitness goals and you should too? Or how horrible aspartame is? Or how bad non-organic food is? Or what you need to eat so you don't get cancer? Or you shouldn't chew gum? Or you shouldn't eat meat?
Honestly, it does little to motivate me when I see someone telling others what to eat when those others haven't ASKED the person what to eat. I think eating healthy is important, of course, but it needs to encouraged. Scolding never works. Sorry, it just doesn't. It only makes the scoldee upset and the scolder looks like one of those stereotypical arrogant fitness or health nuts. (You know the type.)
Lead by example. Do your thing. Eat your food. Do your workouts, but always keep in mind that the other person probably doesn't want to be a CrossFit champ or a Mr. America. Or the next paleo vegan. If they do, they'll ask you for help and advice. Until then, my fitness-nut brothers and sisters, carefully consider what you post on social networks or what you say about what YOU think others should do when it comes to eating and exercise.
And for crying out loud, don't tell them how they should dress either!