Frozen vegetables and fruit high in nutrients

Processed foods have become a sweeping generalisation for anything that comes in a bag or a box.

My nutrition advice usually includes the statement "eat less processed food and choose fresh food instead". But that sentence simplifies a more complex story - how we process food matters.

Some ingredients can undergo changes - like being frozen, fermented or sprouted - that make them equally or more nutritious than they were before. Not all processes are detrimental.

This is how to tell the difference.

ULTRA-PROCESSED FOODS

An apple is more nutritious than applesauce, and both are better choices than apple pie.

The more processed a food is from its original state, the less healthy it becomes.

Take note of what goes into your grocery cart and your body, based on these categories:

1. Unprocessed and minimally processed foods: This group includes basic whole foods such as vegetables, fruit, nuts, eggs, meat and milk.

If the food is processed, it is to preserve the shelf life, such as when freezing vegetables and vacuum- sealing meat.

This group makes up about 30 per cent of the calories we eat.

2. Processed culinary ingredients: These foods enhance the flavour of meals and include olive oil, salt, honey and dried herbs.

Some, like olive oil, are more nutritious than others, like sugar, but they account for only 3 per cent of our calories when used in basic cooking.

3. Processed foods: Foods that undergo some processing and contain just two or three ingredients fall into this group.

Examples are canned fish, salted nuts and sourdough bread. We get about 10 per cent of calories from these foods.

Many of these items are nutritious and make it more convenient to do home-cooked meals.

4. Ultra-processed foods: If you take processed foods such as sugar, enriched flour and high-fructose corn syrup, add food colouring and put them into a Pop-Tart, you get an ultra-processed food.

Such foods are the result of industrial formulations of five or more usually cheap ingredients.

They provide almost 60 per cent of our calories, but that number needs to be much lower.

Collectively, ultra-processed foods are high in sugar, fat and salt, but they lack fibre, vitamins and minerals.

People who consume more ultra- processed foods have a greater risk of obesity, hypertension and high blood sugar levels, which can lead to heart disease and diabetes.

Other examples of ultra-processed foods are candy, instant soups, ice cream, breakfast cereals, soda and hot dogs.

FINDING BETTER PROCESSES

Yogurt with added sugar or powdered cheese in deep-fried potatoes are examples of processes that turn once-healthy food into less nutritious fare.

But not all processes are bad - some forms of preserving and preparing food are very smart ideas.

When you do include processed foods in your grocery cart, consider the following:

•Sprouted food: Whole grains and beans are living seeds, and a little "processing" with the right moisture level and temperature can make them sprout. Sprouted grains and beans are easier to digest, have minimal effect on blood-sugar levels and contain more protein, fibre and B vitamins than non-sprouted counterparts.

•Fermented food: They contain probiotics, which help support the immune system, relieve constipation, help prevent some types of cancer and are being studied for their role in managing cholesterol and treating neurological disorders. Examples are yogurt, kefir (a milk beverage) and tempeh (fermented soya). Or try refrigerated sauerkraut or kimchi, but not the shelf-stable ones, which have been heated or pasteurised, thus killing the probiotics.

•Frozen food: If fresh vegetables wilt in the fridge, use frozen options instead. They are blanched and quick-frozen, which is not detrimental to their nutrients. A comparison study of fresh and frozen vegetables and fruit showed that vitamins C and E are the same or higher in frozen products, compared with fresh ones. So, do stock up on frozen mango, kale and blueberries.

THE WASHINGTON POST

•Registered dietitian Cara Rosenbloom is the president of Words To Eat By, a nutrition communications company in Canada.

A version of this article appeared in the print edition of The Straits Times on February 21, 2017, with the headline 'Frozen vegetables and fruit high in nutrients'. Print Edition | Subscribe