A healthy balanced diet means eating from a variety of food groups to gain the nutrients we need for functioning at our best. We may choose to exclude a particular food group for any number of reasons – faith or religious beliefs, health beliefs, ethical or green reasons, or we may have an allergy or intolerance. Nutrients come under six categories: carbohydrates, protein, fibre, vitamins, minerals, and fat. The main food groups incorporated in this include simple and complex sugars, fruit and vegetables, meat, fish, dairy, nuts, and pulses. Excluding food groups can put us at risk of a deficiency, but with knowledge and careful planning, we can avoid this. Let’s take each in turn
Carbohydrates are our main source of energy and we recommend a healthy diet that contains just over a third of starchy foods, such as potatoes, bread, rice, and pasta. Starchy foods are termed complex sugars, and they release energy slowly over hours (also described by low glycaemic index). They may contain other important nutrients such as fibre, calcium, iron, and the vitamin B group. Simple sugars give a quick short-lived boost (and have a high glycaemic index). These are more likely found in processed foods, sweets and biscuits, and are contributing to the growing obesity problem. Many choose to restrict carbohydrate intake to lose weight. Others may choose this as part of sports training to build muscle mass.
If this is part of a weight loss programme, the aim is to reduce overall calories, so there is no need to "replace" this food group. A good start is reducing simple sugars or replacing them with starchy sugars, so you feel fuller for longer, stopping you snacking and thereby reducing calories. But you should ensure you are getting enough energy to allow the body to tick over. Making healthy choices as part of a recognised regime will be more effective in keeping weight off in the long term, and ensure you’re getting other vital nutrients, such as the fibre that comes with starchy wholegrain foods.
If you are a body builder or need muscle mass for playing sports to a high level, such as rugby, boxing or rowing, you may choose a diet that gets energy from protein rather than carbohydrates. This is a diet rich in red meat, poultry, eggs, dairy, beans and tofu. If done with the right guidance, this can be safe and healthy, and the right food choices can be healthier than taking protein supplements or shakes, but you should be cautious if you have any kidney problems.
If you are following a healthy balanced diet and complete vitamin supplements, you don’t need a blood test to continue with a carb-free diet. If you have any symptoms or medical conditions that may put you at risk, especially if you’re considering a keto diet, you should discuss these with your doctor, who may investigate further. If you have concerns but have no particular symptoms, you can request a private blood test.