Once upon a time carbohydrates provided the mainstay of our diets ? we ate cereals, bread, pasta, rice and potatoes in abundance. Then along came Dr. Atkins and now in the wake of the curb on carbs, many people are eating a huge amount of protein. Bacon and eggs for breakfast, chicken for lunch, steak for dinner and snacks of ham and cheese?. It may sound appealing to some, and may even result in temporary weight loss, but do you really ? honestly ? believe it's healthy?

Firstly let's clear up this carbohydrate issue. The Atkins and South Beach diets both encourage a phase during which absolutely all carbs are avoided.

The theory behind this is that carbohydrates break down into glucose in the body. And if you have excess glucose in the body, this may end up being stored as fat.

Avoiding carbs would prevent this storage of excess glucose, and also encourages your body to burn off fat ? as whilst the body's preferred source of energy is glucose from carbohydrate, it can break down fat to generate glucose instead. However, while fat can be broken down to generate glucose, medical opinion is divided over the value of this.

Some recent research does indicate that the brain can only utilise glucose made from carbohydrate, and not from fat. If true, this would explain why many no-carb dieters say they lack concentration and complain of feeling foggy-headed.

What is certain is that if you avoid carbs, or if your intake is very low over a period of time, negative effects can appear. Many people develop bad breath due to chemicals released as the body converts fat into glucose. So you may be thinner, but no one will want to kiss you! The same chemicals that cause bad breath can also put a huge amount of pressure on the kidneys.

What's worse, by replacing carbs with extra amounts of animal protein, the blood may become very acidic. If this happens then the body will neutralise this acidity by leaching calcium from your bones ? predisposing you to osteoporosis. Also when you do start eating carbohydrates again, your body may more readily store the glucose ? reserving it for brain fuel in the instance of another shortage, but also resulting in weight gain. Finally, many of the protein foods chosen on these diets are also fried (e.g. bacon and eggs), or are naturally high in saturated fat (e.g. steak), both of which are bad for your heart.

However, this doesn't mean that you should now start avoiding protein! Protein is an absolutely essential component of a healthy diet ? here are some examples of the good that quality protein does for your body:

Protein provides you with Protein provides you with amino acids, literally the building blocks of every cell in your body. For example they form the collagen that keeps your skin looking healthy. They are also vital for the development of a strong and healthy musculoskeletal system ? helping to build and repair bones, cartilage, ligaments, teeth and nails.

Protein also helps to buildhormones, and the chemical messengers of the brain and the nervous system.

When eaten at the same time as carbohydrates, protein slows down the rate at which glucose is released from the food ? helping to keep blood sugar well balanced.

The trick is to eat the right amount of protein and to opt for good quality sources. Aim to include one portion of protein as of every meal ? a portion is roughly the size of your palm or fist. (Some people, such as athletes, diabetics or those with liver disorders, may have case-specific protein requirements and should consult their GP, dietician or nutritionist.)

Protein sources that are high in saturated fat are best kept to a minimum ? these include beef, lamb, pork, bacon and full-fat dairy cheeses. Some of you may also prefer to avoid non-organic animal sources of protein, due to some containing hormone and antibiotic residues that can filter through the food chain. Good quality protein includes:

Organic chicken.

Fish, especially cod, talapia, rockfish, wahoo. Try salmon or fresh tuna for an extra dose of good Omega 3 fats.

Unroasted nuts and seeds. Pumpkin seeds are particularly rich in protein ? try sprinkling them on salads or having a handful as a snack with a piece of fruit.

Beans, lentils and chickpeas, especially when combined with a wholegrain ? such as brown rice or quinoa. Wholegrains contain some protein, and combining the two together ensures adequate protein carbohydrate. Quinoa is protein rich ? it looks and cooks like cous-cous and is available at health food shops.

l Tofu. Please don't stop reading now! Some people do find tofu a little bland, but try marinating firm tofu with soy sauce and fresh ginger, and including it in a stir-fry ? delicious! (honestly)

For the majority of people, a healthy diet is a balancing act. We shouldn't rely on one food group to provide us with all the nutrients we need. It isn't healthy to eliminate carbohydrates and to over-do protein, especially if the protein sources you normally eat are those that are high in saturated fat. Focus on good quality protein sources, slow releasing carbohydrates (e.g. brown rice, wholegrain bread and oats instead of refined sugary foods) and plenty of fruit and vegetables.