Ultra-processed foods are back in the headlines, sparking debate around what they are and whether we should be cutting them out of our diet completely. Let’s dive deeper into the science with Carolyn Pallister, registered dietitian and Slimming World’s head of nutrition, research and health…
What are ultra-processed foods?
Researchers in Brazil defined ultra-processed foods by establishing the NOVA classification system, which includes four different food groups:
1. Minimally processed and natural foods: Typically, these include whole fruits, vegetables and wholegrains, meat, rice and grains, fresh or dried fruit, leafy greens, plain yogurt, milk, pasta, granola (with no additives, sweetener or salt) and couscous. Foods that can be ‘processed’ at home are also included – for example, dried, crushed, ground, steamed or boiled.
2. Culinary ingredients: Ingredients obtained from group 1 foods or from nature and industrial processes such as pressing, refining and extracting – such as salt, oils, butter and sugar.
3. Processed foods: Products made by adding salt, oil, sugar or other culinary (group 2) ingredients – for example, canned or bottled vegetables in brine, tinned fruit in juice, salted nuts, salted, dried, cured or smoked meats, canned fish and fresh, unpackaged bread and cheese. These processes aim to increase the shelf life of foods and make them more enjoyable. The products may contain additives.
4. Ultra-processed foods: These products contain long lists of ingredients, many of which won’t be found in your own kitchen – and they’re made using ‘industrial’ processes that can’t be replicated at home. Additives may be used to make foods more palatable or hyper-palatable (even more pleasing to the taste buds). Examples include fizzy drinks, crisps, chocolate, mass-produced packaged breads, margarines (and other spreads) and many pre-prepared, ready-to-heat products (such as pies, pasta and pizza dishes, poultry and fish nuggets/sticks and burgers).
Knowing which foods fit in which categories can be confusing, and there’s often an element of personal judgement required. One of the easiest ways to tell if a food is ultra-processed is to look at the food label. Here are some examples:
Bread
Group 1 – a homemade loaf is considered a minimally processed food
Group 3 – a loaf bought in a bakery that contains just wheat, yeast and salt
Group 4 – a loaf of pre-sliced, mass-produced bread containing additives would fit into the ultra-processed category
Peas
Group 1 – fresh or frozen peas are minimally processed and considered natural foods
Group 3 – peas in a tin are deemed processed
Group 4 – mushy peas fall into the ultra-processed category
Why are these foods in the news?
Ongoing research suggests that a high consumption of ultra-processed foods is associated with poor health, including obesity, cardio-metabolic risks, cancer, type 2 diabetes and cardiovascular disease.
The headlines sound scary, but the research is still in the early stages and can’t yet definitively conclude that ultra-processed foods are the direct cause of these health outcomes.
There’s no denying that some ultra-processed foods (such as chocolate and crisps) are good for us to limit – not purely because they’re ultra-processed, but because they’re high in fat, sugar or both.
The majority of foods we consume nowadays are processed to some degree, often for important or beneficial reasons – eg where they’re fortified to support nutrient intake for convenience, or to make them safer or simply edible. One of the key criticisms of the NOVA classification system is that it doesn’t take the nutrition of the food into account. Although many foods in the ultra-processed category are high in fat, sugar or salt, some of them aren’t – and they may even be considered good sources of nutrients like fibre or protein.
In the UK, some foods (such as bread and cereals) are also fortified with nutrients to help prevent deficiencies. Despite being processed or ultra-processed, these foods can be important nutrient sources for many people.
Following the flood of research and press coverage, the Scientific Advisory Committee on Nutrition (SACN) conducted a review of the evidence in July 2023 and concluded that although the research is worrying, the evidence isn’t currently strong enough to make any changes to dietary recommendations in the UK.
Slimming World and ultra-processed foods
Slimming World’s healthy eating plan, Food Optimising, is carefully designed to support our health and weight – it’s the whole basis (nutritionally and scientifically) of how we designate foods as Free Food, Healthy Extras or Syns. Many of the foods on our Free Food list are unprocessed – including fruit and vegetables, lean meats, fish, poultry, potatoes and eggs. Slimming World members are also encouraged to cook from scratch where they can, which means they’re naturally limiting their intake of highly processed foods.
While some of the foods on the Healthy Extras list (including Slimming World Hi-fi bars) may be classed as processed or ultra-processed, they’ve been carefully selected for their nutritional benefits. They’re also enjoyed in measured amounts.
Foods that have a Syn value (such as crisps, chocolate and alcohol) are enjoyed in moderation on the Slimming World plan, helping to reduce the overall intake of energy-dense processed and ultra-processed foods. No food is banned – our plan is about choice and having the tools to make informed decisions, as well as support to build healthy habits and get the weight loss you want.
When you join Slimming World, you’ll get all the information you need to follow Food Optimising – including a full list of Free Foods and Healthy Extras – in the new member book. You can also use the Food Search tool and barcode scanner on the app to easily see how different foods fit into the plan.
What about the Slimming World food range and Slimming World Kitchen?
Our food range, available in Iceland (or Dunnes Stores in the Republic of Ireland), has been developed to provide satisfying, filling, lower energy-dense alternatives to other ready meals. The meals are as close as possible to those you’d make from scratch in your own kitchen. They don’t have the typical added fats and sugars of other ready meals, and they contain plenty of nutritious, filling Free Foods. They’re perfect for when you don’t have time to cook from scratch and are a healthy alternative to a takeaway.
Slimming World Kitchen recipe boxes make it super-simple to cook healthy meals at home, with easy-to-follow recipes (including quick cook and one-pot dishes) that are packed with Free Food. It’s a convenient option for people who want to eat healthier (whether you’re a Slimming World member or not!), without the stress of meal-planning or time-consuming supermarket trips.
How does Slimming World keep on top of the latest research?
At Slimming World, we have our own in-house team of dietitians, registered nutritionists, data analysts and research scientists – which I’m so proud to lead. Combining our wide-ranging expertise and experience, we work together to ensure that the Slimming World plan develops in line with the latest advances and understanding in food, nutrition, health and weight management.
When you decide to join Slimming World, you can rest assured that our plan is safe, effective and based on five decades – and counting! – of research into the science and psychology of weight loss.
