Food has changed so much over the last hundred years or so that our ancestors would not recognize many of our “foods” as such. While processed foods can be very convenient, they tend to be low in fibre and other key nutrients but energy-dense; while whole foods tend to be nutrient-dense.
Whole foods are defined as foods that are processed and refined as little as possible before being consumed. They are in their natural state (or very close to it) and therefore do not contain additives like salts, fats, preservatives or colourants. Whole foods include fresh fruits and vegetables, meats, poultry, fish, whole grains, legumes (e.g. peas, beans and lentils), nuts and seeds.
An exception to the rule that whole foods are unaltered comes in the form of dairy products. Pasteurization is considered to be a process that doesn't negatively affect the nutritional value of the food; so non-homogenised milks, yoghurts and cheeses can also be called whole foods.
What are processed foods?
Processed foods are foods that have been deliberately altered from their natural state before they are eaten. This broad definition even includes steps like chopping, peeling, freezing or cooking. However, when we refer to processed foods, we generally mean foods that have been subject to heavier processing like canning, juicing, boxing, dehydrating, hydrogenating, extruding etc. Examples of processed foods include breakfast cereals, potato or corn chips, crackers, frozen ready meals, canned foods, sausages, and fizzy drinks.
The food industry processes foods to make them more convenient to cook and eat. They also process foods to preserve them, to increase shelf life and for safety purposes. Processed foods also generally have more than one ingredient, and food manufacturers typically add a host of additives to modify the food products, e.g.:
• Anticaking agents to keep powders from caking
• Antifoaming agents to reduce foaming in liquids
• Bulking agents to increase bulk without affecting nutritional profile
• Food colouring to enhance or mask colors
• Emulsifiers to allow water and oil to remain mixed together
• Flavours (natural and artificial) and flavour enhancers like the widely used monosodium glutamate (MSG)
• Humectants to prevent food from drying out
• Preservatives to prevent spoilage and increase the shelf life
• Stabilizers to prevent separation
• Sweeteners (natural and artificial) like high fructose corn syrup
• Thickeners to increase viscosity
What to choose?
Your best food choices are those that are closest to nature. Processed food products may last longer on the shelf, but the tradeoff is that they will have lost a lot of their nutritional value. The following are examples of choosing whole foods over their processed counterparts:
• Fresh, lean chicken breast instead of frozen chicken nuggets
• Whole fruit instead of canned fruit in syrup
• Plain milk instead of flavoured milkshakes
• Low fat real cheese instead of processed cheese spread in a jar
• Whole potatoes instead of a box of instant mashed potatoes
• Fresh corn on the cob instead of canned creamed sweetcorn
Tips for buying whole foods
Shop the perimeter of the store – that’s where the fresh foods are! The foods towards the middle of the store are generally packaged in layers of plastic and cardboard and are definitely more processed. Also, choose produce markets over supermarkets; they have less packaged and processed foods available to tempt you. Do a weekly grocery shop and you will be less tempted to stock up on processed foods that tend to have long shelf lives.
Always look at the ingredient listings. The rule of thumb is that the longer the list of ingredients and the more unfamiliar and unpronounceable the words – the more processed it is! Ideally a food should have one ingredient – itself! The fewer ingredients on the label, the better.