Do food supplements help with weight loss? What they add and what they do not

What a supplement actually is

A food supplement is a concentrated source of nutrients, usually vitamins, minerals or other substances, sold in doses such as tablets, capsules or powders. In the UK it is legally a food, not a medicine. It is designed to add to your normal meals, not to replace them. The NHS says that most people should get all the nutrients they need from a varied and balanced diet, although some people need extra.

Where a supplement can genuinely help

• Vitamin D in autumn and winter. Government advice is that everyone should consider a daily vitamin D supplement in the darker months, when our skin makes very little from the sun. A winter walk along the Hessle foreshore is good for you, but it will not cover your needs in December.
• Specific life stages. Folic acid before and in early pregnancy is a well known example.
• A diet that leaves out whole food groups. People who eat no animal products, for example, often need vitamin B12.
• A deficiency found by your GP. Iron or vitamin B12 after a blood test, at the dose your GP advises.

In each of these cases the supplement corrects a shortfall that food alone is not covering. When you are eating less to lose weight, it is also worth checking that the meals you keep still bring enough variety, because a smaller plate leaves less room for vitamins and minerals. A coloured plate with vegetables, fruit, pulses, dairy or fortified alternatives and some oily fish each week does most of the work. It supports your health and your energy, which makes healthy habits easier to keep. It does not burn fat.

What supplements do not do

• They do not melt fat. Be wary of any product that promises to burn fat, block calories or speed up your metabolism in a dramatic way.
• They do not cancel out a takeaway. A tablet taken after a heavy meal changes nothing about that meal.
• They do not replace food. The British Dietetic Association reminds us that no supplement can provide the same benefits as a healthy balanced diet.
• More is not better. Taking high doses can cause side effects, and some vitamins build up in the body over time.

Safety checks before you buy

The same BDA fact sheet warns that some supplements can interact with medicines, including blood thinners, some antibiotics, antidepressants and the contraceptive pill. Products bought from unknown websites may contain less of the active ingredient than claimed, or ingredients that could harm you. The British Dietetic Association also suggests that if you buy online, you choose a recognised high street retailer that trades online too. So before buying anything, check 3 things.

• Do I take any regular medicine? If yes, ask your pharmacist or GP first.
• Am I pregnant, breastfeeding or living with a long-term condition? Again, ask first.
• Does the seller look reputable, with a clear label, a dose and a UK address?

Food first, in practice

For most people trying to lose weight, the nutrients that make the biggest difference come from ordinary food. Protein at each meal helps you feel satisfied and contributes to the maintenance of muscle mass, and our page on how much protein you need each day gives simple portions. Fibre from vegetables, pulses, oats and wholegrains keeps you fuller for longer, as explained in our guide to feeling fuller for longer. For an overview of each vitamin and where to find it in food, see our guide to vitamins.

A balanced breakfast, every morning

At Willerby Nutrition the day starts with breakfast at the club, Monday to Friday from 7am and on Saturday from 8am, and the coaches follow members every day. If you are unsure where your diet stands, the free assessment at the club is a calm place to start, with a look at your meals and a measure of muscle, fat and water.

This page is general information and does not replace advice from your GP, your pharmacist or another health professional.