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. What harmful substances are you eating? Here’s what our Hong Kong tests found 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. “ Too much sodium in our diet can lead to high blood pressure , strokes and heart disease . It also causes calcium loss, which may affect bone health ,” Cheung says. How to understand nutrition labels and choose healthy foods Sugar is a quick and readily available source of energy, but it too can be bad for us, with excessive amounts increasing the risk of high blood pressure, diabetes , inflammation and fatty liver disease – all of which have been found to contribute to heart disease and strokes. A high sugar intake is also linked to obesity and tooth decay . According to Cheung, if you adhere to the typically recommended 2,000-calorie diet for adults, you shouldn’t consume more than 30g of sugar per day. 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). “I would advise against buying products containing artificial sweeteners. Animal studies suggest that saccharin [E954], sucralose [E955] and stevia [E960] may change the composition of our gut microbiome . Artificial sweeteners are also believed to cause cravings for sugary foods,” he says. Processed meats like bacon, sausages and luncheon meat may be convenient, versatile and easy to prepare but they are classified by the World Health Organization as Group 1 carcinogens. These meats are known to increase our risk of stomach cancer and bowel cancer. “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. How foods like instant noodles are causing a child malnutrition crisis 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. “Frozen fruit and vegetables are also worth stocking up on because they’re just as nutritious as their fresh counterparts, and you can’t go wrong with canned products like beans , chickpeas and tuna – choose plain-flavoured and water-packed varieties that don’t contain added salt or oil,” says Luk. “Unsweetened, calcium-fortified soy milk and tofu are great alternatives to dairy products. Tofu fortified with omega-3 is a healthy choice for people who don’t eat seafood.” 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. Like what you read? Follow SCMP Lifestyle on Facebook , Twitter and Instagram . You can also sign up for our eNewsletter here .