If you follow wellness content on social media or in the news, you’ve probably heard that processed food is not just unhealthy, but can cause serious harm.

Eating a diet dominated by highly processed foods means you’re likely to consume more kilojoules than you need, and greater amounts of salt, sugar – as well as food additives.

But not all processed foods are equal, nor bad for you. Here’s what to look out for on food labels if you want to buy processed, but convenient, foods.

What do the processing categories mean?

Researchers use the Nova processed food classification system to group foods into four processing levels.

Group 1: Unprocessed or minimally processed foods are either in their natural state or have minimal processing. They’re basic foods you could eat straight away, such as vegetables and fruit, or foods that only need minimal processing to make them safe and palatable, such as eggs, meat, poultry, fish, oats, other grains, plain pasta, legumes, milk, plain yoghurt, ground herbs and spices, or nuts with shells.

Group 2: Processed culinary ingredients are derived from group 1. These are used in cooking to enhance flavour and texture, and include oils, sugar and honey.

Group 3: Processed foods are treated using traditional processing methods such as canning, bottling, fermenting, or salting to extend shelf life. These include canned fruits, tomato paste, cheese, salted fish, and breads with minimal ingredients. You could make these foods in a home kitchen.

Group 4: Ultra-processed foods are industrially produced with ingredients and additives not normally found in home kitchens, and have little, if any, group 1 items left intact. These foods are engineered to be hyper-palatable, meaning you can’t stop eating them, and have long shelf lives. Products include factory-made biscuits, snack foods, instant meals, frozen desserts, preserved meats, instant noodles, margarine, some breakfast cereals and sugar-sweetened drinks.

However, group 4 products vary greatly in their nutritional quality and the number and type of food additives used to manufacture them.

What’s the concern about eating lots of ultra-processed foods?

About 42% of Australians’ total energy intake comes from ultra-processed foods. These are relatively cheap and are energy-dense, but nutrient-poor. This means they can contain a lot of kilojules, salt and added sugars but are poor sources of nutrients the body needs such as vitamins, minerals and dietary fibre.

Studies have linked higher intakes of ultra-processed foods with poorer diet quality and worse health outcomes. A review of 122 observational studies found people with the highest intakes (compared with the lowest) were about 25% more likely to have had a decline in kidney function. They were 20% more likely to be overweight, or have obesity or diabetes, and were 40% more likely to have common mental health conditions such as depression.

However, a recent review highlighted that the health impact of these foods and drinks varies depending on their category. Products such as sugar-sweetened drinks can negatively affect health, while others – such as cereals with added vitamins and minerals and some dairy products – can be neutral or even protective.

Some level of food processing can improve food safety, extend shelf life and reduce food waste. This is likely to include the use of additives, such as emulsifiers, flavour enhancers, preservatives, food acids, colours and raising agents. Additives need to be approved by Food Standards Australia and New Zealand (FSANZ) after a safety assessment, with the lowest amount added to achieve the specific purpose in the food product.

However, some adults and children eat a lot of ultra-processed foods. This means they have high intakes of food additives, in terms of total amount and different types.

Researchers have raised concerns about a potential link between high intakes and increased risks of some health conditions, ranging from mental health disorders to heart disease and metabolic disorders such as diabetes. The researchers called for transparent use of evidence to ensure public health messaging is kept up to date.

An observational study in more than 100,000 French adults also raised concerns about potential “cocktail” effects of food additive combinations. Although more research is needed, they found some additive combinations were associated with a higher risk for developing type 2 diabetes.

Finally, a recent review highlighted the potential for additives, particularly emulsifiers, to damage the gut lining and alter the balance of healthy versus unhealthy gut microbes. This could potentially increase the risk of developing inflammatory bowel conditions.

What processed foods should you choose?

It depends on how they’re made, the additives used, how often you eat them, and how much you have.

When choosing processed foods:

1. Read the ingredient list on the food label. It tells you a lot about the level of processing and additives used. Look for products that contain minimal to no additives, and ingredients that could be found in a home kitchen. Note that additives could be listed by name or number.
2. If there are a number of products in the same category, choose the one with more Health Stars as it will contain less salt, saturated fat and added sugars, compared to products with fewer Health Stars.
3. Think about how often you eat the product. If you do eat it weekly or more often, spend more time comparing products before making a final choice.

While you might expect all Nova 3 processed foods to be healthier than Nova group 4 (ultra-processed), this isn’t always the case. Nova group 3 items don’t necessarily meet the nutrient criteria that deems them “healthy”. They could still contain excessive amounts of added salt, saturated fat or sugars.

For help to review the level of processing alongside the nutrient criteria, consider using an app such as Open Food Facts. This assigns food products a Nova group score, a nutrition score, and another to rate its impact on the environment.

Clare Collins, Laureate Professor in Nutrition and Dietetics, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It’s that time of year when many people are getting started on their resolutions for the year ahead. Doing more physical activity is a popular and worthwhile goal.

If you’re hoping to be more active in 2024, perhaps you’ve invested in an activity tracker, or you’re considering buying one.

But what are the benefits of activity trackers? And will a basic tracker do the trick, or do you need a fancy one with lots of features? Let’s take a look.

Why use an activity tracker?

One of the most powerful predictors for being active is whether or not you are monitoring how active you are.

Most people have a vague idea of how active they are, but this is inaccurate a lot of the time. Once people consciously start to keep track of how much activity they do, they often realise it’s less than what they thought, and this motivates them to be more active.

You can self-monitor without an activity tracker (just by writing down what you do), but this method is hard to keep up in the long run and it’s also a lot less accurate compared to devices that track your every move 24/7.

By tracking steps or “activity minutes” you can ascertain whether or not you are meeting the physical activity guidelines (150 minutes of moderate to vigorous physical activity per week).

It also allows you to track how you’re progressing with any personal activity goals, and view your progress over time. All this would be difficult without an activity tracker.

Research has shown the most popular brands of activity trackers are generally reliable when it comes to tracking basic measures such as steps and activity minutes.

But wait, there’s more

Many activity trackers on the market nowadays track a range of other measures which their manufacturers promote as important in monitoring health and fitness. But is this really the case? Let’s look at some of these.

Resting heart rate

This is your heart rate at rest, which is normally somewhere between 60 and 100 beats per minute. Your resting heart rate will gradually go down as you become fitter, especially if you’re doing a lot of high-intensity exercise. Your risk of dying of any cause (all-cause mortality) is much lower when you have a low resting heart rate.

So, it is useful to keep an eye on your resting heart rate. Activity trackers are pretty good at tracking it, but you can also easily measure your heart rate by monitoring your pulse and using a stopwatch.

Heart rate during exercise

Activity trackers will also measure your heart rate when you’re active. To improve fitness efficiently, professional athletes focus on having their heart rate in certain “zones” when they’re exercising – so knowing their heart rate during exercise is important.

But if you just want to be more active and healthier, without a specific training goal in mind, you can exercise at a level that feels good to you and not worry about your heart rate during activity. The most important thing is that you’re being active.

Also, a dedicated heart rate monitor with a strap around your chest will do a much better job at measuring your actual heart rate compared to an activity tracker worn around your wrist.

Maximal heart rate

This is the hardest your heart could beat when you’re active, not something you could sustain very long. Your maximal heart rate is not influenced by how much exercise you do, or your fitness level.

Most activity trackers don’t measure it accurately anyway, so you might as well forget about this one.

VO₂max

Your muscles need oxygen to work. The more oxygen your body can process, the harder you can work, and therefore the fitter you are.

VO₂max is the volume (V) of oxygen (O₂) we could breathe maximally (max) over a one minute interval, expressed as millilitres of oxygen per kilogram of body weight per minute (ml/kg/min). Inactive women and men would have a VO₂max lower than 30 and 40 ml/kg/min, respectively. A reasonably good VO₂max would be mid thirties and higher for women and mid forties and higher for men.

VO₂max is another measure of fitness that correlates well with all-cause mortality: the higher it is, the lower your risk of dying.

For athletes, VO₂max is usually measured in a lab on a treadmill while wearing a mask that measures oxygen consumption. Activity trackers instead look at your running speed (using a GPS chip) and your heart rate and compare these measures to values from other people.

If you can run fast with a low heart rate your tracker will assume you are relatively fit, resulting in a higher VO₂max. These estimates are not very accurate as they are based on lots of assumptions. However, the error of the measurement is reasonably consistent. This means if your VO₂max is gradually increasing, you are likely to be getting fitter.

So what’s the take-home message? Focus on how many steps you take every day or the number of activity minutes you achieve. Even a basic activity tracker will measure these factors relatively accurately. There is no real need to track other measures and pay more for an activity tracker that records them, unless you are getting really serious about exercise.

Corneel Vandelanotte, Professorial Research Fellow: Physical Activity and Health, CQUniversity Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.