Many diets that have shown to be successful in helping people get their diabetes under control share a common factor; they are all relatively low in carbohydrate.
We take a look here at a number of diets and look at how successful they are at treating diabetes and whether they count as low-carb.
Note that if you have diabetes, it is important to consult your doctor before making any significant change in your diet. This is especially important for people on diabetes medication that can cause hypos.
Low fat diet
A low-fat diet is typically not a low-carbohydrate diet. Whilst low-calorie, low fat diets can lead to weight loss, they are not very effective at improving blood glucose levels.
When compared against low-carb diets, low-fat diets typically perform poorly in terms of blood glucose control and are ineffective at helping people to reduce their dependence on diabetes medication.
Long-term studies have also showed that low-fat diets perform poorly in terms of preventing heart disease.
The Mediterranean Diet
The Mediterranean diet refers to diets that are based around fresh foods, a strong intake of vegetables and natural sources of fat.
The diet has varied quite substantially in research trials, with some trials testing low-carbohydrate Mediterranean diets and other trials using a higher-carbohydrate, whole grain version of the diet.
The combination of fresh foods, plenty of vegetables and a low-carbohydrate intake has shown itself to be an effective approach:
- Low carb Mediterranean diet outperforms low fat diet over 8 year study
- Mediterranean diet outperforms low-fat diet for weight loss, say researchers
Very-low calorie diets (Newcastle diet)
A very-low-calorie diet made the headlines in 2011, when researchers from Newcastle University were able to reverse the effects of type 2 diabetes in a small study of 11 participants.
The diet used involved meal replacement shakes which provided 600 kcal, plus participants were able to have up to 200 kcal from non-starchy vegetables.
The shakes used provide around 20g of carbohydrate per serving and the diet was therefore low in carbohydrate as well as being very low in calories.
In a larger trial, that is currently running, initial findings show that the average weight loss was 14kg and diet had helped 40 per cent of participants to reverse their type 2 diabetes 6 months after the diet period had been completed.
It is important that people looking to follow this diet receive approval and medical supervision from doctor.
Read more about the Newcastle diet
Ketogenic diets are very-low carbohydrate diets that have been used for over a hundred years to treat epilepsy.
Research has also shown the diet to be very effective in treating type 2 diabetes by reducing HbA1c, body weight and triglyceride levels
Anecdotal evidence indicates that a ketogenic diet is also effective in treating type 1 diabetes, however, no significant trials have tested this.
People looking to follow a ketogenic should seek approval and medical supervision from their doctor.
Diets involving long-periods of fasting are going to be low in carbohydrate by definition.
Long periods of fasting are possible for people who are overweight as long as they get vitamins and minerals in broth form or from supplements and are closely supervised by their doctor.
Intermittent fasting diets, however, may or may not be low-carb. For example, the 5:2 diet will involve significant fasting two days per week which will involve a low intake of carbs. The other 5 days may or may not low-carb depending on how much carbohydrate the person chooses to have on these non-fasting days.
Intermittent fasting diets present an option for people looking to lose weight who prefer having carbohydrate based meals rather than low-carb meals.
Note that blood glucose control is likely to be better if the non-fasting days are low-carb as well.
The Paleo diet is intended to be similar to the diets our ancestors in the Paleolithic era which was before farming was developed.
People on a Paleo diet therefore avoid grains and most sources of starchy carbohydrate. As a result, a Paleo diet tends to be fairly low-carb.
The other key health property of the diet is that it aims to avoid any processed food
So far studies into the effects of a paleo diet have been relatively small scale and the evidence of success in terms of managing diabetes is mainly anecdotal.
One striking anecdote of the success of a Paleo diet is the story of a newly-diagnosed nine-year-old boy with type 1 diabetes, who was able to come off insulin injections for two years by following a ketogenic Paleo diet.
Raw food diet
A raw food diet is based around foods that are eaten raw such as vegetables, fruit and nuts. The diet is typically relatively low in carbs as starchy foods usually need to be cooked.
The raw food diet has seen some impressive anecdotal results, with people reporting that they have lost significant weight and reduced their medication requirements. 
Studies that are not diabetes-specific indicate that long-term adherence to raw food diets can lower total cholesterol but also lowers levels of HDL cholesterol which is needed to protect against heart disease. 
So far, there is a lack of clinical trials to investigate how effective the diet may be in treating diabetes in the general population.