In an interview with the Radio Times, the actor said: “I'm part of the lazy American generation that has blindly kept dancing through the party and now finds ourselves with a malady.
“I was heavy. You've seen me in movies, you know what I looked like. I was a total idiot.
"I thought I could avoid it by removing the buns from my cheeseburgers. Well, it takes a little bit more than that."
So, is Hanks being too hard on himself or is a healthy diet the key to avoiding diabetes?
There are two types of diabetes, Type 1 and Type 2. Hanks was diagnosed with the latter in 2013.
While Type 1 diabetes cannot be prevented, more than half (58%) of cases of Type 2 diabetes can be delayed or prevented by making simple changes in our everyday lives.
According to Diabetes UK, Type 2 diabetes occurs when the body doesn't produce enough insulin to function properly, or the body’s cells don't react to insulin.
Symptoms include feeling the need to go to the toilet a lot, being really thirsty, feeling more tired than usual, unexplained weight loss and genital itching or thrush.
Causes of the disease are related to both genetics, which we can't control, and lifestyle choices, which we can.
According to the NHS, a person is considered at a higher risk of developing Type 2 diabetes if they are a overweight or obese, are over the age of 40 (over 25 for south Asian people), have a close relative with the condition or if they are of South Asian, Chinese, African-Caribbean or black African origin.
Dr Helen Webberley, the GP for oxfordonlinepharmacy.co.uk, says it is possible to rectify past lifestyle choices relating to diabetes.
"We now know that diet can impact our long-term health from as early on as the womb, where we can be affected by what our mother our consumes," she tells The Huffington Post UK.
"High sugar and high fat diets are well-known to be harmful to both current and future health. But it is never too late to adopt a healthier lifestyle.
"Smoking, weight and exercise all contribute to longevity and small changes can make big impacts."
She adds that there is no point beating yourself up about past bad habits.
"Change for the future and encourage any youngsters under our influence to adopt healthier patterns of living," she says.
The NHS advises that anyone concerned about Type 2 diabetes can reduce their risk by doing the following:
eating a healthy, balanced diet
losing weight (if you're overweight) and maintaining a healthy weight
stopping smoking (if you smoke)
drinking alcohol in moderation
taking plenty of regular exercise
If you've already been diagnosed with Type 2 diabetes, making these changes will also minimise your risk of developing complications such as vision loss, heart disease and kidney failure.
In his recent interview, Hanks said doctors believe he will no longer be affected by symptoms of Type 2 diabetes if he reaches the target weight they've set.
Radio Times is on sale from Tuesday 17 May.