This is a great question - there have been a lot of low-carb diets advocated recently for many reasons, including reduced insulin secretion, ketosis and just to create a calorie deficit.

Whilst any of these rational's may be an excellent explanation in isolation, the critical aspect to practically all these low-carb diets is that they do not consider the wider picture - that carbohydrates are an essential nutrient required for many bodily functions and to promote good health.

Extreme cases aside (ie. if you are critically ill and have been prescribed a low-carb diet by a medical practitioner or nutritionist), a low-carb diet can be very unhealthy. It is important to understand that carbohydrates are nutrients, responsible for many essential processes within the human body. Here are some critical functions carbs perform within our body's:

• Provide energy
• Sparing the use of proteins for energy
• Assisting the breakdown of fatty acids
• Preventing ketosis (a medical condition)
• Biological recognition processes
• Flavour and sweetener
• Aid in maintaining normal cholesterol levels
• Aid in maintaining normal blood glucose levels
• Support bowel regularity

In fact, the significant reduction of carbohydrates in your diet can lead to a whole host of problems, including:

• Constipation
• Loss of energy
• Bad breath
• Loss of concentration
• Kidney stones
• Kidney infections
• Reduced kidney function
• Gout
• Diabetes
• Osteoporosis
• Cancer
• Irritable bowel syndrome, severe abdominal pain or cramps
• Vertigo, dizziness or light-headedness
• Nausea
• Severe menstrual problems
• Diarrhoea

Interestingly, the only source of energy that your brain can utilise is carbohydrate. So this would explain why you are experiencing a significant decrease in concentration and focus. This is a clear warning sign that your body chemistry is unbalanced.

Meanwhile if we consider insulin, it is a common marketing practice to promote a particular molecule as something to be avoided altogether in a blanket statement approach (eg. carbs, fats, insulin etc.). However insulin actually performs many functions within the body that are highly important, including:

• Glucose Metabolism
• Stimulates lipogenesis
• Diminishes lipolysis
• Increases amino acid transport into cells
• Modulates transcription
• Altering the cell content of numerous mRNAs
• Stimulates growth
• DNA synthesis
• Cell replication

Insulin is a hormone that is necessary for the normal functioning of the human body. Trying to suppress insulin secretion in an unnatural manner (eliminating carbohydrates from your diet is an unnatural approach to nutrition), you risk placing your body at risk of various health complications.

I would suggest to seek independent professional advice regarding both nutrition and exercise for weight loss. A healthy approach is the most effective way to lose weight in a sustainable manner. This will include carbohydrates, as they are necessary for the normal functioning of the human body.