How Much Sugar Is Too Much Sugar?

As many of us know, having too much sugar is problematic for a number of reasons such as, increasing the risk ofdeveloping diabetes. This, in turn, can cause a variety of health complications, such as kidney damage, nerve damage, and cardiovascular issues. This is because eating too much sugar is also associated with obesity.

However, when trying to determine how far to limit sugar consumption, many people struggle to know how much sugar is too much. When considering the fact that there are differences between natural sugars and added sugars, and that different amounts of each should be consumed in a day, it becomes more complicated to understand just how much sugar a person can safely eat in a day.

According to the American Health Association, the recommended amount of added sugar in a day varies between men and women:1

  • Men should not consume more than 36 grams of added sugar a day
  • Women should not consume more than 25 grams of added sugar in a day

There is a difference between naturally occurring sugars and added sugars, and this will be explored further.

It is important to note that sugar is not dangerous. It is an important fuel for many of the processes that help our cells to live, and us to remain alive. It is only dangerous when it is consumed excessively. Remember that moderation is important and that the amount is what makes something dangerous.

What to know about sugar

The type of sugar that you’d typically pick up at the supermarket in a bag, is a sweet-tasting molecule that is naturally produced. Sugar, or sucrose (which is the scientific term for it), is made up of two building blocks glucose and fructose.

When carbohydrates and complex sugars (which are sugars that have two or more building blocks) break down in the body, they are turned into glucose, which is small enough for our cells to use.

Glucose is very important in the body. Cells use it as an immediate source of energy as it is readily available and easy to use in respiration (which is the process our bodies go through to produce energy). Other sources of energy, like fats and proteins, need to be modified before being used, so are less efficient.

On food labels, sugars might be called:2

  • Fructose
  • Fruit juice concentrates
  • High fructose corn syrup
  • Malt syrup
  • Nectars
  • Naltodextrin

Recently, more and more foods have been containing artificial sweeteners which are a low calorie way to sweeten foods. These will often have ‘-itol’ as the ending, for example, mannitol, xylitol and erythritol.

How much sugar is enough?

As mentioned above, there are guidelines published on how much sugar should be consumed per day:

  • For men, this is no more than 36 grams of added or free sugars a day
  • For women, this is no more than 25 grams of added or free sugars a day

Naturally occurring sugars are not counted in these figures as these are not as dangerous towards a person’s health. This is explored below.

What is the difference between natural and added sugars?

The thing that often confuses people is the difference between natural and added sugars. Simply put, natural sugars are sugars naturally found in foods – this includes the sugars in fruit and dairy products such as milk.

Added sugars (sometimes called ‘free sugars’), on the other hand, refers to any sugar that is added to a food during its preparation – for example, sugar that is added to coffee, cereal, a fizzy drink, or chocolate.

The reason it is important to distinguish between the two is because naturally occurring sugars are typically healthier to consume; this is because naturally occurring sugars are typically consumed with something a lot more difficult for the body to digest, like fibre, dairy or fats.

This is important because things like fibre, fats and dairy take longer to break down in the body and so naturally occurring sugars are absorbed more slowly.

On the other hand, added sugars are not typically consumed with something complex – for example, very few people would eat their favourite chocolate bar with broccoli, which is high in fibre. For this reason, added sugars are absorbed much quicker, causing a spike in a person’s glucose levels.

What are the consequences of too much added sugar?

Too much added sugar is dangerous as it can cause a person’s glucose levels to spike, as mentioned above.

When a person’s glucose levels spike, it causes the pancreas (an organ that sits close to the liver) to release a hormone, or messenger, known as insulin. Insulin is a messenger because it sends a signal to the cells to take the glucose and use it for energy.

However, the glucose levels will quickly return to normal when this happens, and once the cells have used all the sugar, they will send signals that they need more. This is what usually prompts a person to have more sugar. The easiest and most readily available source of this sugar will typically be another food that is high in added sugars. The cycle then repeats itself.

The constant spikes and crashes are problematic as they promote the consumption of excessive sugar. This can then contribute to a phenomenon known as insulin resistance.

Insulin resistance is when the cells in the body do not respond properly to insulin’s message – meaning that they do not take up the sugar that is floating around in the bloodstream. This causes the body to do one of two things:3, 4

  • Store the extra sugar in the liver or as fat
  • Produce extra insulin to ‘convince’ the cells to take the extra sugar

Both of these are problematic as the first option can contribute to weight gain and non-alcoholic fatty liver disease and the second one means that the pancreas has to produce more and more insulin, which the cells will become less and less responsive to. This eventually ‘wears out’ the pancreas’ cells, contributing to the development of diabetes.

As many people are already aware, diabetes often comes hand in hand with other illnesses, like obesity and cardiovascular problems. However, it can also cause kidney and nerve damage if it is not well controlled. Furthermore, living with diabetes is horrible on its own as many adults with diabetes have to take medication every day, monitor their glucose levels, and sometimes inject themselves with insulin.

As a result, it is important to reduce the amount of sugar in your diet – this does not have to be completely cut out, but a reduction will make a huge difference.

Tips to reduce sugar intake

Sugar seems to be everywhere, and it can be really difficult to reduce your sugar intake. The good news is that the only kind of sugar that most people need to cut down on is added sugar. The NHS provides some good tips to help people reduce their sugar intake:5

  • Eating alternatives to cereal, as cereals often have added sugars
  • Swapping out your regular fizzy drink for a no-sugar option, for example switching from Coca Cola to Coke Zero
  • Slowly reducing the amount of sugar you put in teas and coffees
  • Use semi-skimmed or skimmed milk
  • Eating wholemeal bread
  • Using less condiments like ketchup
  • Reducing the number of sugary snacks you eat, whether this be by having one biscuit a day instead of two, or by having ‘no sugar’ days

It is also important to eat foods that have a low glycaemic index. The glycaemic index is a measure of the effect of food on our blood glucose levels, and this impacts insulin response.

Foods with a high glycaemic index will cause a spike in blood sugar levels (and insulin levels) which can contribute to the development of diabetes 6. This is not to say that all foods with a high glycaemic index are unhealthy. For example, watermelon, which has a high glycaemic index, is healthier than crisps, which have a comparatively low glycaemic index. 

Foods with a low glycaemic index can be higher in fats, and therefore calories 7. However, consideration should be given to the glycaemic index of foods, especially if you have or are at risk of developing diabetes. Focusing on the overall glycaemic index of a meal can help to manage your sugar levels.

Foods with low glycaemic indexes include:

  • Whole grain foods, like oats and porridge
  • Pulses and lentils
  • Green vegetables


The most important takeaway message is that, in general, you should aim to eat below the recommended allowance of added sugars per day. This is 36 grams for men and 25 grams for women. This is because eating less sugar is the best way to prevent illnesses, like diabetes from developing.

Sugar is categorised into two types – added sugars and natural sugars. Natural sugars are found in things like fruit. These will typically contain a lot of fibre that makes them less likely to cause an insulin spike.

Added sugars are typically the ones to reduce, as they are typically found in foods that are low in other nutrients like proteins, healthy fats, and fibre. As a result, they can cause spikes in blood glucose levels, which in turn raises the amount of insulin that the pancreas releases. This contributes to insulin resistance which is a precursor (meaning something that comes before or can lead to) to diabetes.

Insulin resistance is where the cells start to respond less positively to insulin. As a result, the pancreas will produce more insulin to ‘persuade’ the cells to take the sugar from the blood, or the liver will store the extra sugar as fat.

Eating foods that are lower in added sugars, or foods that have a lower glycaemic index, can be important in helping to manage blood sugar levels. This can also help to reduce the likelihood of developing diabetes.

However, the best and most important way to reduce the likelihood of developing diabetes is by ensuring that you eat a diet that is rich in different nutrients, vitamins, and minerals. A balanced diet will ensure that you fuel your body adequately.

Ensuring that you are physically active is also important as this will not only help you to ensure your heart and the rest of your body is healthy, but it will also help promote your cells to use sugar as a fuel, reducing insulin resistance.


  1. American Heart Association. How much sugar is too much? [Internet]. 2019. Available from:
  2. Different Words for Sugar on Food Labels [Internet]. 2013. Available from:
  3. Insulin Resistance - Symptoms, Causes, Treatment [Internet]. 2019. Available from:
  4. Insulin Resistance | ADA [Internet]. Available from:
  5. NHS. How to cut down on sugar in your diet [Internet]. 2022. Available from:
  6. Glycaemic index and diabetes [Internet]. Diabetes UK. 2017. Available from:
  7. NHS Choices. What is the glycaemic index (GI)? [Internet]. NHS. 2019. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Aisha Hayat

Bachelor of Science - BS, Biomedical Sciences, General, University of Bristol

Aisha is a Biomedical Sciences graduate with an understanding about research techniques, the pharmacology of drugs and the pathophysiology of illnesses. She is currently working as a healthcare assistant and has experience of research being used in a clinical setting, as well as the process of diagnosing and treating illnesses. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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