The link between being overweight and risk of diabetes

With more and more people being diagnosed with diabetes every year, it’s definitely a risk to wake up to if you are overweight. It’s believed that obesity accounts for 80-85% of the risk of developing type 2 diabetes. The charity Diabetes UK suggests that up to 80% of cases of type 2 diabetes can be delayed or prevented by making simple diet and lifestyle changes.

In addition to being overweight, other risk factors for diabetes include:

  • Your ethnicity; people from African-Caribbean, Black African, Chinese or South Asian backgrounds over the age of 25 are more at risk
  • Your age; risk increases past age 40 for people from other backgrounds
  • Family history; sibling or parent with diabetes
  • Medical history; previous heart attack, stroke, or polycystic ovaries (PCOS)
  • Medical diagnosis; being diagnosed with ‘pre-diabetes’ (sometimes called ‘impaired fasting glycaemia’ or ‘impaired glucose tolerance’) and/or having high blood pressure
  • Pregnancy-related risks; gestational diabetes during pregnancy, and/or giving birth to a baby over 10lbs (4.5kg)

This article refers to type 2 diabetes, which accounts for around 90% of people with diabetes. This type of diabetes is different to type 1 diabetes which is an autoimmune disease often diagnosed in childhood, and requires insulin treatment from the outset. With type 2 diabetes, the pancreas either isn’t producing enough insulin to maintain normal blood sugar levels, or the body isn’t able to use the insulin it’s producing – known as ‘insulin resistance’. Often people will start by being ‘diet controlled’, and may move on to medications or even insulin as the disease progresses over time.

Why does being overweight increase my risk?

Whilst carrying excess weight is a well-known risk factor for type 2 diabetes, scientists are still not sure about the exact mechanisms by which being overweight or obese cause diabetes.

It’s a myth that diabetes is caused by eating too much sugar or sugary foods. The fact is that being overweight is a big risk factor of developing diabetes, and eating too much sugar or sugary food is linked to weight gain. By regularly eating foods high in sugar (and fat) like cakes, biscuits, pastries, chocolate, and sugary drinks, you increase your calorie intake, and thereby increase your chances of gaining weight.

However, although body mass index (BMI) is an important measurement, it’s perhaps not the most important factor. What really increases your risk of diabetes is your body shape; the amount of weight (fat) you carry around your middle and upper body. You may have seen this measurement referred to as ‘waist circumference’. It is quite possible for someone to have a healthy BMI, but have too large a waist measurement. This means if you are an ‘apple shaped’ person – prone to storing more fat around your middle (and less around your hips and thighs), you may be more at risk of diabetes than a ‘pear shaped’ person (who stores less fat around their middle and more around their hips and thighs) even with the same BMI.

Being overweight, and in particular having a large waist circumference indicates you’re carrying too much fat. Fat stored centrally, around key organs like your heart, liver and pancreas, can result in insulin resistance – where your fat cells have become resistant to your natural insulin production. This results in too much sugar staying in the blood stream, rather than entering your fat cells.

The following table shows the measurement cut-offs for significantly increased risk of diabetes (and cardiovascular disease). If you haven’t already done so, try measuring yourself (instructions in the final section) – if your waist is higher than these below, then you really need to take stock:

White94cm (37 inches)80cm (31.5 inches)
Black94cm (37 inches)80cm (31.5 inches)
Asian90cm (35 inches)80cm (31.5 inches)

Table taken from

How can losing weight help?

Research has shown that losing as little as 5-10% of your weight can result in significantly reducing insulin resistance.

If you already have diabetes, whilst you can’t reverse it, there’s good news for you too on the benefits of weight loss front. Losing 5-10% of your body weight can significantly reduce your HbA1c, and can also reduce your blood pressure and cholesterol if these are raised too.

Losing over 10% of body weight has even more significant improvements.

Research suggests that obese people (BMI over 30) are 80 times more likely to develop type 2 diabetes than those with a BMI of less than 22 – that’s a staggering statistic! A BMI of 22 may seem like a future pipe dream – a long way off, but hopefully the fact that losing just 5% will have a big difference too will motivate you to keep going. For a 15 stone person, this means losing just 10lbs, which is a much more realistic short-term goal.

What else can you do to help reduce your risk?

The following tips will help you to understand your risk factors and how to start making changes.

    • Be aware of your risk factors – whilst you can’t change some of your risk factors (such as age or ethnicity), it’s still important to review the risk factors for diabetes, especially those you can change. You could consider getting an NHS Health Check with your GP or Practice Nurse. The NHS Choices website also has a type 2 diabetes self-assessment tool.
    • Know your numbers – Most people tend to weigh themselves regularly, but do you measure your waist circumference as well? You waist size is not necessarily your trouser size. To measure yourself, you will need to find the mid-point between the bottom of your rib cage and the top of your hip bone; measure around this point, and take the best of three measurements. Measure this monthly, alongside your usual weekly weights. Some people see really positive reductions in waist circumference without significant reductions in weight, which can be motivating.
    • Decide on the best approach to weight loss – you will need to make changes to your diet and get the right support in order to lose weight and keep it off for good. How you do this is the tricky bit! But trying a Slim & Save programme might be a good option for you.
    • Slash your sugar and fat – if you have already been diagnosed with diabetes or pre-diabetes, now is the time to really take action. The British Heart Foundation have produced a labelling ‘decoder’ – a useful tool that can be used to help you choose lower fat and lower sugar foods, by reviewing the nutrient content per 100g of food. It’s a really useful way to start looking at reducing your intake. You can download the PDF from here.
    • The new Change 4 Life Sugar Smart App is another really useful tool to help you cut back on your sugar intake.
    • Exercise – has a big role to play in reducing risk of diabetes. Whilst increasing you exercise levels can help you lose weight, regular exercise is also known to increase your body’s sensitivity to insulin (thereby reducing insulin resistance). Just 30 minutes of moderate-intensity exercise a day can help you achieve this benefit.

Written by Annemarie Aburrow RD BSc (Hons) PGDip, Slim & Save Dietitian.


  1. I was diagnosed with type 2 diabetes after struggling with my weight for 30 years. I have been on this diet for just over a week and feel so much better. I have more energy have lost some weight but most importantly my blood glucose is back to normal. I still have a long way to go with the weight loss, this is the first diet that has worked for me. Thank you for all of your support so far x

  2. I have been type 2 diabetic for 10 years I started on oral meds, then meds and victosa jab, I have been on full-on inuslin for 4 years and my sugars were always above 15 and so my dossage of insulin was increasing rapidly i was having 58-60 units of slow acting insulin twice a day and between 25 and 31 units of fast acting insulin 3 times a day thats with 4 metformin a day and victosa jab once a day.. I started slim and save 6 weeks ago and I havent had one sugar reading above 7, I am having 44 units of long acting insulin and 4 units of fast acting and that just one jab of fast acting.I am not tired not sweating not having the intense exausted feeling my constant swollen legs and feet are now normal I have lost 46lb and I dont even feel like I am on a diet,I have enjoyed every S&S product I have had, I have done mostly simplicity days but have had a couple of life syle days, I cant wait to see my doctors face when I tell him how I am doing and he can see that I have lost the weight.. I have a long way to go but thats ok I accept that. Please remember I am type 2 diabetic and I have my doctors support I am not saying that it will work for everyone, but its worth a try but only with your doctors support xx

  3. its definitely an added incentive to lose weight, especially now that peoples lifestyles have such an impact on their health. Its something that I have not really thought of before but its now something that I will be taking seriously!
    The health affects are definitely more of a priority than my original goal of looking better.

  4. Most of my family have had or do have diabetes so the importance of me loosing weight is paramount I’m 5’4 14.13 as of Monday and 42 years old and so my weight loss really means so much xx thanks for posting this .

  5. Very interesting read and a wake up call, me and many other people need to see. It’s easy to put weight on we all know, but getting it off isn’t so easy. I think a lot of people can quite easily get overweight without realising the consequences. We have both Diabetes (Only effects Males) and Heart Disease in our family. The wake up call I needed was when my Father who is subsequently Type 2 Diabetic, had problems with what we thought was poor circulation. When we managed to get him to a Dr (doesn’t like a fuss), he was sent for tests. When they done an ECG, Treadmill and Angiogram which all come back inconclusive, they kept him in. We are so lucky that we forced him to go to a Dr because apart from them symptoms he had none. We we’re by the look of God very, very lucky because he was that ill, if he had a Heart Attack we would have lost him. Nobody would have had the equipment to save him. I don’t want to have Diabetes, never mind Heart Disease. Dad was overweight but not excessively, bit of a tummy but he walked our two dogs for three hours per day, never smoked and not a big drinker. You never know the minute so trying to do something about it is the first step to preventing Heart Disease and worse still Diabetes… Good Luck Guys and Girls, it’s the start to new you..

  6. Too many people wait until diabetes has taken hold and then lose weight. A shame that we let it go that far before we act. My father was one of them. However since I introduced him to slim and save he has had his medication halved and will soon be off it all together 🙂 Thanks to this diet. We need this diet out there more to help others. I for sure am very grateful I found Slim and Save!!

  7. Since doing this diet i have lowered my BMI enough rotake me out of the prediabetic stage and lowered my cholestrol and glood glucose blood test. On days i find it difficult i remind myself rgat im increasing my life span

  8. As someone who is very overweight I recognise that its easier to be “blind” to the problems you are causing for yourself. It is so easy to dissociate the act of over-eating from the outcomes.
    It’s good to read articles like this that remind you of the harm you are doing to yourself in a clear, factual but non-judgemental way. Thank you.

  9. Wow, what an interesting read. Never realised how high risk I was! I always thought over eating was the answer, I’d have never thought it could have such detrimental effects. Thanks to S&S I have now come put of the obese category and will continue losing weight to reduce the risk!

  10. As a newly qualified pharmacy dispenser, it’s been quite a shocking revelation how many people are taking type 2 diabetic medicines. A majority of these are down to poor diet/obesity and could be avoided. Some people assume dieting is just because you’re bothered how you look and don’t even consider the numerous health implications. Well done SNS for highlighting health issues.

  11. I have a brother that has diabeties and there is nothing he is doing about it eg losing some weight, he seems quite happy to go through life using the injections, I realized that I am older by 2 years and I have disabled children that rely on me, I also have a daughter who is overweight but with her autism she is unaware of the problems. then I thought to myself, how can I explain to my daughter the risks about health when I am not doing anything for myself? this article has also given me more incentive to continue on losing the weight. I am keeping a private journal about how im feeling daily, this then hopefully will help me figure out how to approach my daughters journey. the quicker I lose the weight, the quicker I can help my daughter and possibly show my brother that he too has a different option that he could also take. thank you for the article.

  12. This has given me new strength to lose weight. I started iniatlly because i was fed up of beeing fat and tired. Then i nearly lost my mother because of a heart problem. That made me think of my children. I want to be healthy for them and for my mother so i can look out for all of them afterall i love them all ☺️❤️❤️

  13. My family has a history of this and I found it extremely helpful to know that I can make a change to my lifestyle and hopefully not have this happen to me. I think this kind of knowledge should be taught to you in school because i always thought it came from a love of sugery sweets and drinks( how I loved them) and now I know it’s actually from carrying excess weight. It was also very good to know how it effects different ethnicity as well. This is why I started this slim and save journey because I want to be healthier and none of us know what the future holds and making simple life decisions for a better lifestyle choice can be passed on to friends and family and I would deffo recommend slim and save because I have found it to be a pleasure to do and am so happy with the fact that at the end of this journey I will have extended my life expectancy and lowered any risks that I may have been heading towards. Thank you slim
    And save.

  14. The more people that realise the risks we carry caused by the extra weight we carry then I think more of us would strive to lose the extra baggage. Not only has losing 5 stone made me feel healthier and happier but after reading this extremely informative and interesting article I also realised that I have dramatically reduced my risk of diabetes! Well done….great work!

  15. A very informative article thanks for sharing.

    About 12 months ago i was diagnosed as pre-diabetes, but luckily after cutting out most of my sugar and starting to lose weight i managed to control it and touch wood have been lucky enough for it to have gone back to normal, so here’s to hoping it stays that way

  16. Very interesting. The research has been out for years but somehow the weight creeps on before we know it.

    Need to shift the tummy tyre, to prevent our pancreas getting tired. We need the insulin, so let’s hit the gym. With slim and save we are sure to win!

  17. My family have diabetes, my grandparents auntie and cousins seeing what they go thru on a daily basis is horrible! If people could limit this by doing something very positive just by changing their eating habits surely it’s worth a go! Not only do slim and save help that but the help and information they give is amazing!! I’m glad that I hopefully will reach my goal and not have to worry about deliberating illnesses like diabetes
    Laura x

  18. Very interesting and informative article. It is an epedemic and I think we all need to take it seriously. Thankfully with the support of the Slim and Save plan I am managing to control weight and waist size. Thank you.

  19. Very informative article and its highly likely that there are so many more underlying issues that need to be addressed immediately to ensure we are healthy asap! It is a shame we can’t all have access to private full body scans!

  20. Great artical, I currently have pcos and that can lead to diabetes, my dad also has t2 diabetes so it could be hereditary too for me, pcos and then risk of diabetes is why I’m doing slim and save to reduce my weight and improve my health including reducing the risk of type 2 diabetes, I watch my dad inject his insulin every day and I don’t want to go through that…

  21. I am already a T2 diabetic and use insulin, completely agree with all of the above and slim & save has been a huge help to lose weight, still got a way to go but getting there!

  22. Love this article. My family have a history of type 2 diabetes and are often dissalusioned as to why they have it. My mother was recently diagnosed with it and was told it was due to her lifestyle, she has put on about 3 stone in the past 3 years and this has impacted massively on her health. I myself am constantly trying to improve my health to ensure that I dont ever get diabetes, I regularly exercise and eat healthily and have recently started Slim & Save to help me reduce my weight. I love the fact that there are meal replacement plans as good as Slim & Save which give people the opportunity to lose weight and become healthier in themselves.

    Personally I think there should be more information in regards to weight loss programmes when people are diagnosed with type 2 diabetes. Often people are just diagnosed and told they need to make changes but hardly gain any good advice in how to do so.

  23. Not only was this article informative but I found it an eye opener, I just took for granted being overweight that I was uncomfortable within myself and hated the way I looked on the outside. To realise the damage being caused in the inside terrifies me and has given me that extra push to become happier and healthier. The additional tools provided within the article are also going to encourage me on the correct path great links and advice.

  24. I’m a mix of caribbean and Indian aswell as Irish and all of my grandparents had diabetes, so this was a real eye opener as I’m probably at a higher risk than I even realised. I may even be further down the path to diabetes than I realise. I’m taking control of my weight now, before it’s too late. Slim & Save Simplicity, me and you are going to do this journey together!

  25. This is a really interesting article, I also tried the NHS self assessment test which put me at high risk. I have PCOS and carry a lot of weight round my stomach, I am also insulin resistant so am really pleased I have started Slim and Save! I should be back in the healthy range in no time at all, thank you!

  26. What an excellent article I never knew the waist measurement was so easy to monitor. However I’ve never had a waist even as a size 8 I had no curves but using this as a guide is really cool. S&S has really helped me lose 50% of my target weight so far and is reducing my risk everyday which is a massive positive step. learning from this article has enpowered me to take a more positive approach to healthy living – thank you

  27. I am lucky and reduced my high blood pressure with Slim and Save. I used to take two lots of tablets twice a day for high blood pressure which was a concern just like diabetese.
    People need to be re-educated about poor diet, lack of excercise and consequences. I know this isn’t always easy but with support this can sometimes be achieved. I have found the link interesting which gives full information about the whole spectrum about diabetes.

  28. I myself have pre diabetes and my Gp and diabetic nurse did not explain things as clearly as they are in this article! So helpful and full of the right information on the risks and how to help yourself. Thank you Annemarie and team x

  29. A very informative article – to someone in their mid 20s who thought they were ‘too young’ to have to worry about diabetes – it has been a real eye opener. Thanks Annemarie and the Slim&Save team.

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