This story has been updated.

Among the essential activities allowed during mandatory stay-at-home orders caused by the coronavirus pandemic is grocery shopping, but most experts agree that residents should cut back on the number of trips they make to the store as part of their social-distancing strategy.

One key to doing that is to create a list of essentials and stick to it, said Joanna Michalowska, a dietitian and doctoral candidate from the Medical University of Poznan in Poland, who worked with a team of health professionals there to create a tool — the Omni Food Calculator — designed to help people understand how much food they need for a two-week period.

“When something like this happens, we don’t know what’s going on, how to behave,” Michalowska said.

Her advice is to first do an inventory of the pantry, refrigerator and freezer. Then, create a healthy meal plan for the next two weeks. Finally, make that grocery list.

The team at Poznan demonstrated how to do this by using software designed to create a handful of healthful meal plans that emphasize lean protein, fruit, whole grains and vegetables. They subbed in items with longer shelf life. For example, you won’t find strawberries under fruit, but you will find apples.

The team then applied multipliers, so people can enter the number of adults and children in their household and calculate how much perishable, nonperishable, canned/frozen and fresh foods they might need to follow the meal plans.

The recommendations in the calculator must be adjusted to suit your own tastes and the availability of foods.

The calculator is based on the specific meal plan developed by Michalowska. Those daily eating plans are plant-based with little meat included. They rely heavily on eggs, for example, as a protein source. So, while she might recommend that three people need 45 eggs for a 14-day period — about one egg a day per person — if your family gets its protein from another source, you may require fewer eggs. Also, because there is a shortage of eggs right now, substituting other sources of lean protein, such as chicken breasts or tofu, may be required.

“You’ll be surprised at how little you need, even for 14 days,” she said, stressing that the team also wanted to discourage hoarding.

“Don’t panic-buy,” she said. “That’s the most important thing. Think: What do you need and what will you eat? Think there are other people in this world. Other people also need these things.”

Making healthy choices is essential, she said. She predicts that many will gain weight during the pandemic. (Her meal plans include the occasional treat.)

“In Poland, at the beginning, all the pasta and rice started to disappear, but also sweets,” she said. “I was thinking, if you’re preparing for quarantine, you should have essentials, not just junk food, especially because we’re not getting as much physical activity.”

She offers these general tips for shoppers:

  • Stick to the list of essentials. Prepare to vary based on availability, but don’t be swayed because an item is in stock or you see others buying it.
  • Don’t overstock. It leads to waste and prevents others from getting essential items. Check the dates on perishable foods to be sure you’ll be able to consume all of it before it goes bad.
  • Choose nourishing products with long use-by dates, such as whole-grain pastas, brown rice, canned milks, seeds, grains and legumes.
  • Avoid unhealthy snacks and sweets. “You will eat all of them really quickly if you stay at home,” she said.
  • Buy products that you will use even after the pandemic is over. Don’t buy items that you don’t like or are allergic to just because they have a long use-by date and are available.

The last tip is important because it doesn’t do any good to buy pounds of apples, for example, if no one in your house enjoys them.

“You can’t build a meal plan that is good for every person,” Michalowska said of the calculator, noting that tastes, availability and health requirements vary. Still, she said, she hopes the calculator and meal plans can serve as a guide as people navigate strategies for staying healthy and slowing the pandemic.

More from Voraciously

People are baking bread like crazy, and now we’re running out of flour and yeast

If you suddenly need to learn to cook, these resources will help guide you

No flour, butter or eggs? We have 6 sweet recipes for that.