Portion sizes of food such as muffins, slices and scones, would also be reduced.
A report on the guidelines said the new rules would have "a small impact" on Wairarapa Hospital, as it had already made some changes to support healthy food choices.
It had got rid of sugary fizzy drinks, offering diet versions instead, and reduced the portion sizes of baked items in its cafe.
But fish and chips is offered one to two times a week meaning the meal would have to be cooked differently or be removed from the menu.
Also labelled "red" are processed meats like bacon, salami and ham with high sodium, saturated fat and energy content.
Food labelled "amber" includes rice, sandwiches with full fat cheese in them, high-energy smoothies, full-fat milk and yoghurt, and toasted muesli.
The focus of the guideline is on providing "green" foods, low in sugar and saturated fat and added salt and dominated by wholegrains, vegetables and fruit.
Last month, the 3DHB Executive Leadership Team recommended Wellington, Hutt Valley and Wairarapa hospitals adopt the guideline and then as policy in 18 months - "a long transition timeframe" to allow the DHBs to notify and negotiate with suppliers. The rationale behind the guidelines is for the hospitals to act as a role model.
"Unhealthy food and beverages, low levels of physical activity and obesity contribute to many illnesses which are very common and increasing in our communities," the report said.
"Policy and environmental change have been identified as the foundation of obesity prevention in an environment that promotes eating too much and moving too little."
The guidelines won't stop people from bringing "red" foods into hospitals. They apply to food and drink for sale at the hospital, any fundraisers associated with the hospitals and any gifts offered to guest speakers or formal visitors on behalf of the hospitals. It doesn't apply to patient meals.
Capital and Coast DHB has also voted to adopt the guidelines and Hutt Valley DHB is to consider them today.