Ultra-processed foods have been in the media a lot lately, with new research suggesting that they cause weight gain and may increase the risk of heart attack, stroke and ultimately death. They can be described as “formulations mostly of cheap industrial sources of dietary energy and nutrients plus additives, using a series of processes, and containing minimal whole foods”. One of the more popular methods for identifying ultra-processed foods is the NOVA system which classifies all foods and food products into one of four groups:
- Unprocessed or minimally processed foods. Edible parts of plants or of animals, and also fungi, algae and water, after separation from nature. Minimally processed foods are natural foods altered by processes that include removal of inedible or unwanted parts, and drying, crushing, grinding, fractioning, filtering, roasting, boiling, non-alcoholic fermentation, pasteurization, refrigeration, chilling, freezing, placing in containers and vacuum-packaging.
- Processed culinary ingredients. Include oils, butter, sugar, flour and salt. They are substances derived from Group 1 foods or from nature by processes that include pressing, refining, grinding, milling and drying. They are not meant to be consumed by themselves, and are normally used in combination with Group 1 foods to make freshly prepared drinks, dishes and meals.
- Processed foods. Include canned vegetables, seafood, fruits in syrup, cheeses and freshly made breads, are made essentially by adding salt, oil, sugar, flour or other substances from Group 2 to Group 1 foods. Processes include various preservation or cooking methods, and, in the case of breads and cheese, non-alcoholic fermentation. Most processed foods have two or three ingredients, and are recognizable as modified versions of Group 1 foods. They are edible by themselves or, more usually, in combination with other foods.
- Ultra-processed foods. Include soft drinks, sweet or savoury packaged snacks, reconstituted meat products and pre-prepared frozen dishes. They are not modified foods but formulations made mostly or entirely from substances derived from foods and additives, with little if any intact Group 1 foods.
With all of the protein claims on the labels of packaged foods, and the associated health halos, it is hard for many people to swallow the fact that most of these ultra-processed snack foods are largely sources of junk protein – highly refined and purified extracts from Group 1 foods, largely devoid of vitamins, minerals or any other essential nutrients, but fortified with a sprinkling of a select few vitamins/minerals to make them look more nutritious than they really are.
Additionally, most people in the developed world meet their Estimated Average Requirement (EAR: the daily nutrient level estimated to meet the requirements of half the healthy population) for protein without the need for supplementary protein in the form of ultra-processed snacks. For example, in Australia, the EAR for protein for men is 0.68g per kg body weight per day and for women it is 0.60g per kg body weight per day. Australia’s most recent nutrition survey in 2011/12 determined that men consumed an average of 104.6g of protein per day or 1.2g per kg body weight and women consumed 77.9g of protein per day or 1.1g per kg body weight. In other words, the average Australian man and woman consumed nearly twice as much protein as the Estimated Average Requirement each day.
What happens to the excess ultra-processed protein that we consume? Unlike carbohydrates and fats, we are unable to store excess protein as such. Like any other nutrient, proteins can be converted into other forms of energy, however. Many of the amino acids that make up proteins can be converted into the carbohydrate glucose which can be stored as glycogen in liver and muscles. The nitrogen portion of the amino acid molecule is excreted as urea in the urine. Just like it can from other dietary sources, glucose from protein metabolism can also be converted to fat and stored in our fat cells.
For your daily protein requirements, enjoy minimally-processed foods like beans, chickpeas, lentils, nuts and seeds, wholegrains, meat, poultry, seafood, eggs, milk and yoghurt. Save ultra-processed foods, including those high in protein, for special occasions – they are not daily fare.
Read more:
• The UN Decade of Nutrition, the NOVA food classification and the trouble with ultra-processing
• Australian Health Survey - protein
Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).
Contact: You can follow him on Twitter or check out his website.