Dominic Hughes and Michael Race are business reporters.
Diners in England will see calories on the menu.
Restaurants, cafes and scurries with more than 250 staff must show how many calories are in their meals on their websites and delivery platforms.
The new rule is part of the government's plan to tackle obesity.
Some restaurants fear it will increase their costs, while an eating disorder charity says it could contribute to harmful thoughts and behaviors.
Large food and drink businesses in England with 250 or more employees must display the calories of their non-prepacked food and soft drinks.
Some chains on the High Street publish information about the calories in their food. McDonald's has been doing it for a long time.
The co- founder of the Mexican-style street food restaurant said the chain was up for being transparent with customers. He said the focus on counting calories was a problem.
He said that it tells part of the story but misses out on some important aspects of food.
Mr Selby said that people wouldn't look at the menu from a calories point of view.
He said that creating a system to ensure that chefs were using the right amount of ingredients in their restaurants had an impact on the business and increased costs.
The company added the carbon footprint of meals to measure the climate impact of each dish.
The change was a terrible thing to happen to the industry. He warned that the regulation could end creativity and lead to boring cooking.
Kids will grow up in restaurants, hotels and cafes only looking at the number below a dish. The choices will be based on a number. He said that the love of flavour, ingredients, history, cooking craft or nutrition will be lost and masked by a newly perceived focus.
The new rules came at the worst possible time for thousands of businesses struggling to survive, according to Kate Nicholls, boss of the industry group UK Hospitality.
We have long called for a delay to the implementation of the new rules, and we would like to see a grace period post-April to allow businesses breathing space in which to implement the new rules without the risk of unnecessary enforcement action from day one.
Businesses devastated by Covid should not be expected to introduce complicated and costly new labelling when they have more pressing matters to attend to.
The change won't make a difference to Charlotte Roberts' food choices.
The 19-year-old said that he came to the restaurant because he knew what he wanted to eat. I eat what I want to eat.
James Howlett said the change wouldn't affect his menu choices. The 18-year-old said that he didn't notice that they didn't have it down.
It is what I feel like on the day. If I want a pizza, I will take a pizza, if I want a burger, I will take a burger.
Patrick Callaghan said the move would make a difference to which dish he picked.
I think people care about what they eat and particularly after the lock down, people are conscious of being more active and taking an interest in the calories that they take into the body.
Kate Callaghan said people should accept their own responsibility for what they eat.
Beat, the UK's eating disorder charity, says that making calories on the menu mandatory can contribute to harmful eating disorder thoughts.
The director of external affairs for the charity said there was evidence that calories cause anxiety and distress for people affected by eating disorders.
He said that it can increase a fixation on restricting calories for those with eating disorders.
There is not much evidence that the legislation will change eating habits among the general population.
The government has been asked by Beat to consider the impact on people affected by eating disorders and to consult experts at every stage of the process.
The Department of Health and Social Care said that food labelling was an important part of helping people make healthier choices and that it was one of the biggest health issues the country faced.
People are used to seeing nutrition information on products in supermarkets.
The government consulted with mental health charities and experts when it came to its policy.