Explainer | A guide to processed foods, what to avoid and how to tell which can be eaten as part of a healthy diet, according to a doctor and a dietitian
- As prices go up, more of us are turning to processed foods as a convenient and affordable meal option, and the best part is that they’re not all unhealthy
- From how to decipher ingredient labels to the types of additives to avoid, here are some tips from a doctor and a dietitian for buying healthy processed foods
Post-pandemic stresses on supply chains have pushed food prices up. That means many of us are looking to save money by cooking meals at home instead of dining out, and relying more on processed foods – which are generally easier to prepare and cheaper than their fresh counterparts.
But what exactly qualifies as processed food, and why are ingredients processed in the first place?
According to Cyrus Luk Siu-lun, a dietitian and executive committee member of the Hong Kong Dietitians Association, processed food is any raw agricultural product that’s been washed, cleaned, milled, cut, chopped, heated, pasteurised, blanched, cooked, canned, frozen, dried, dehydrated, mixed or packaged.
It is also those foods to which preservatives, flavours, nutrients, salt, sugar, fat and/or other food additives have been added.
The reasons behind processing include eliminating unhealthy microorganisms, extending shelf life, ensuring availability throughout the year, and enhancing flavour.
All this may sound a little unhealthy, but there’s good news for those who want to continue cooking with, or simply can’t live without, moreish processed foods: they’re not all bad for you.
“Processed foods can certainly form part of a nutritious and balanced diet, but to make the right choices, you have to first look at their nutrition label and ingredient list,” says Luk.
“Make sure that the product is free from shortening [fat that is a solid at room temperature], hydrogenated oil, margarine, creamer, animal fat, palm oil and coconut oil, as these ingredients contribute to a product’s overall saturated and trans fat content. Healthy processed foods tend to be low in these bad fats.”
Too much saturated fat in our diet can raise the amount of “bad” low-density lipoprotein (LDL) cholesterol in our blood, which may increase our risk of heart disease and strokes.
“Women should not consume more than 20g [0.7oz] of saturated fat per day, and men, no more than 30g,” says Dr Gordon Cheung Chak-man, a general practitioner from The London Medical Clinic, in Hong Kong’s Central business district.
Saturated and trans fats are commonly found in processed products such as pastries and other baked goods, creamers, processed meat, and fried foods.
The salt used in food processing is usually sodium chloride. According to Cheung, we only need a small amount of sodium – about 500mg per day – for processes like muscle relaxation and contraction, nerve function, and to maintain the balance of water and minerals in our body.
Luk points out that there is also evidence to suggest that the intake of food colouring – including E102 (tartrazine), E104 (quinoline yellow), E110 (sunset yellow FCF), E122 (carmoisine), E124 (ponceau 4R) and E129 (allura red) – can lead to worse behaviour in children with attention-deficit hyperactive disorder (ADHD).
“Research has found that there are certain chemicals in processed meats, including N-nitroso-compounds (NOC) and polycyclic aromatic hydrocarbons (PAH), that cause them to be carcinogenic,” Cheung says.
As well as being high in fat, foods that have undergone high-temperature, dry-heat cooking methods like deep-frying and baking also contain carcinogens, such as acetaldehyde, acrolein, benzene, 1,3-butadiene, ethylene oxide, heterocyclic amines and polycyclic aromatic hydrocarbons, says Luk.
How can you tell if a product is minimally or highly processed?
Besides checking the nutrition label to determine how much saturated fat, trans fat, sugar and salt the food contains, look at the order in which the ingredients are listed.
“The ingredients are often listed in the order of weight, so the main ingredients in the product always come first,” says Cheung.
“If the first few ingredients are high-fat ones like cream, oil or butter, for example, then that tells you that the food contains mostly fat.”
Processed foods that offer little to no nutritional value include instant noodles, which contain high amounts of salt and are often fried in oil before being packaged; frozen ready meals, which tend to be loaded with preservatives, sugar, salt and fat; and factory-made cakes and pastries, which are high in saturated and trans fats and refined sugar.
Margarine – which is high in trans fats – is also relatively unhealthy, as are deli meats, crisps, soft drinks, sweetened yogurt, and non-dairy coffee creamer.
Conversely, there are many processed foods that make a healthy addition to your diet, such as dried, wholegrain pasta; breakfast cereals that are low in sugar, salt and fat; and pre-cooked plain rice.
For a healthy snack, Cheung recommends nuts that have been roasted without added salt, sugar or oil. Natural Greek yogurt is an excellent source of calcium – essential for bone health – and probiotics, which are good for the gut.