Spot the difference

Ever wondered what the difference is between low-fat and reduced-fat, nutritionists and dietitians, or salt and sodium? If so, you’re not alone. In my years as a dietician, I’ve come across many who are flummoxed by the jargon used to describe health-related products and conditions. It’s a problem that can be confusing at best and dangerous at worst, so here is the low-down on some of the most confusing terms.

Low-fat and reduced-fat

• By law, a food labelled as low-fat must contain no more than 3g of fat per 100g.

• Reduced-fat foods must contain at least 25 per cent less fat than a similar product. This means reduced-fat products often have a reasonably high-fat content. For example, reduced-fat cheese may still contain 14g fat per 100g.

Food allergy and food intolerance

• Food allergies involve the immune system. Allergens such as cow’s-milk protein, eggs or nuts can cause the body to react and produce antibodies. These usually cause immediate and severe symptoms, such as swollen lips and eyes, vomiting, skin hives and – in extreme cases – breathing difficulties or even death.

• A food intolerance doesn’t usually involve the immune system. Symptoms – such as stomach cramps, bloating and constipation – often appear hours or days after eating the offending food. Specific tests are available to diagnose allergies but not intolerances, making the latter harder to identify. If you suspect you have either you should see your GP for advice.

Dietitian and nutritionist

• The title ‘dietitian’ is protected by law. Anyone calling themselves a dietitian must be registered with the Health Professions Council and is therefore fully qualified. This means that if you see a dietitian you are guaranteed to receive accurate advice based on sound science.

• The term ‘nutritionist’ is not currently protected, so anyone can call themselves one. This means the quality and quantity of training can vary widely, although there are plenty of good nutritionists – many of whom are members of the Nutrition Society.

The title ‘dietitian’ is protected by law. Anyone calling themselves a dietitian must be registered with the Health Professions Council. The term ‘nutritionist’ is not currently protected, so anyone can call themselves one.

Kilocalories and kilojoules

• Food labels give energy values in kilocalories (kcals) and kilojoules (kJ). These units are used to measure energy, just as pounds and kilos are used to measure weight. In the UK, most of us use kilocalories, (which we shorten to calories or ‘kcals’).

• Kilojoules are a more modern way of measuring energy. They are used by scientists and countries that have ‘gone metric’. One kcal is equivalent to 4.2kJ, so the value for kJ is always higher.

Omega-6 and Omega-3

• Omega-6 fats are found in oils and spreads made from corn, sunflower and soya. They provide an essential fatty acid called linoleic acid.

• Omega-3 fats are found in flaxseeds, rapeseed oil, nuts, and green leafy vegetables such as broccoli and cabbage. 

• They provide the essential fatty acid alpha-linolenic acid (ALA), of which around 10-15 per cent is converted by the body into two long-chain polyunsaturates called EPA and DHA. Oily fish provide EPA and DHA directly and are considered to be one of the best natural sources of omega-3s.

• Both omega-6 and omega-3 fats are polyunsaturated fats. They lower blood cholesterol but omega-3s, particularly from oily fish, seem to have an even greater benefit for heart health. Experts recommend eating one portion of oil-rich fish every week – choose from salmon, trout, mackerel, sardines, pilchards, herring, anchovies and fresh tuna.

Soluble and insoluble fibre

• Good sources of soluble fibre include fruit, vegetables, oats, barley and pulses. Soluble fibre helps to keep blood-sugar levels steady and may lower blood cholesterol.

• Good sources of insoluble fibre include wholemeal bread, wholegrain cereals, brown rice, wholemeal pasta, grains, nuts, seeds, and vegetables eaten with the skin. Insoluble fibre keeps the digestive system healthy by increasing the bulk and softness of the stools, so they pass easily through the body, preventing bowel complaints like constipation. Fruit is another good source when eaten with the peel (apples, peaches and pears) or seeds (berries). To get all the health benefits, it’s best to eat a mixture of both kinds of fibre.

Sodium and salt

• Sodium is one of the components of salt – also known as sodium chloride – and eating too much is linked to high blood pressure.

• Health experts recommend we eat no more than 6g of salt a day, equivalent to 2.4g of sodium.

• To calculate the salt content of a product, multiply the sodium value by 2.5. The Food Standards Agency suggests foods with 1.25g of salt or 0.5g of sodium per 100g or more are high in salt. Those containing 0.25g salt or 0.1g sodium per 100g or less are low in salt.