The number of people living with diabetes in the UK has tipped over the 4 million mark for the first time, according to 2016 figures released by Diabetes UK.

[Read more: Could you have diabetes? 5 hidden symptoms of diabetes that could mean you're suffering]

But the good news is that because most of the 59.8% increase in diagnosis is in type 2 diabetes cases, simple diet and lifestyle changes can help reverse the trend.

Diabetes UK says there are now a total of 3.6 million people diagnosed with diabetes in the UK, compared to nearly 2.1 million in 2005.

However, many cases are type 2 diabetes, which is the form often linked to diet and obesity. And that means for some people, a diabetes-healthy lifestyle can control the illness, which is thought to be on the rise because of increasing obesity levels.

Such a lifestyle includes losing weight if you're overweight, eating a healthy diet including lots of fruit and vegetables, and exercising. These measures can help reduce blood-sugar levels, and either reduce or even stop any diabetes symptoms.

And while some people with type 2 diabetes need to take medication, making these healthy diet and lifestyle choices can mean they don't need to take their tablets any more. People with type 1 diabetes, however, will always need insulin injections.

[Read more: Call for better diabetes treatment]

What's the difference between type 1 and type 2 diabetes?

While both type 1 and type 2 diabetes are characterised by having higher than normal blood-sugar levels, the cause and development of the conditions are different.

Type 1 diabetes is an autoimmune disease that means sufferers are unable to produce the hormone insulin, which helps the body use glucose in the blood to produce energy. The immune system attacks insulin-producing beta cells in the pancreas, and people with type 1 diabetes need to inject themselves with insulin to control their blood-glucose levels. This form of the disease usually starts in childhood.

In type 2 diabetes, the body still produces insulin but loses its ability to respond to it. This is known as insulin resistance. The body compensates for the ineffectiveness of its insulin by producing more, but it can't always produce enough.

The more excess body weight a person carries, the less sensitive they are to insulin.

Type 2 diabetes usually appears in people over the age of 40, though in South Asian people, it often appears from the age of 25. It's also increasingly common in children.

It's often associated with obesity, high blood pressure and/or high cholesterol levels.

Diabetes symptoms

Symptoms of both types of diabetes can include:

- Increased thirst
- Increased hunger
- Dry mouth
- Frequent urination
- Unexplained weight loss
- Fatigue
- Blurred vision
- Headaches
- Recurrent infections
- Slow healing of cuts and grazes

With type 2 diabetes there are often no symptoms, or only a very gradual development of them, until complications occur. Such complications can be severe, including nerve damage, loss of vision and organ damage.