Pros and cons of low carb, high protein with type 1

A low carb, high protein diet refers to restricting your carbohydrate (carb) intake while increasing your protein intake, predominately through animal proteins, eg red and white meat, seafood and eggs.

Its aim is to achieve your daily nutrient, health management and/or weight loss goals.

These types of diets generally focus on limiting refined carbohydrate rich foods and drinks such as high carb processed and packaged foods eg chips, biscuits, cakes, pastries, lollies, ice cream, and sugar-sweetened drinks including soft drinks, cordials, energy and sports drinks, and flavoured milk.

However, in most cases low carb, high protein diets also restrict nutritious carb-rich foods from the five core food groups such as:

  1. Wholegrains and wholegrain products: breads, cereals, pasta
  2. Dairy products: milk, yoghurt, cheese
  3. Carb-rich vegetables: legumes, corn, potatoes
  4. Fruit

These foods are full of beneficial nutrients such as fibre, vitamins, minerals, antioxidants and other helpful plant chemicals.

There is not one low carb, high protein diet or standardised approach but instead many variations.  Generally, a low carb diet refers to less than 26% total energy from carbohydrates per day while a moderate carb diet is between 26-45%.

The Australian Dietary Guidelines recommend between 45-65%, which is considered a moderate to higher carbohydrate diet, which most largely plant based eating styles are. So what does that look like in grams per day?

A low carb diet would contain less than 130g carbohydrates per day for someone following a diet of 8,400kJ (2000 calories).  A moderate carbohydrate diet would contain 130-225g carbohydrates per day.  In terms of protein, a higher protein diet can range from around 1-1.5g per kg of total body weight.

There are various low carb diets in the media such as Ketogenic (Keto), Atkins, Paleo and Optifast, although each of them follow slightly different rules.  Some diets may focus on quality, nutrient-rich carbohydrate food choices, while others may focus purely on the amount of carbohydrates eaten.


A common theme of low carb diets is an initial success in weight loss and improved post prandial (after eating) blood glucose levels.  Seeing these results in the first few weeks can boost confidence levels and lead to increased adherence (continuing with the diet).

Initial weight loss and improvements in blood glucose levels may result from various reasons.

Most likely, it is due to the reduced intake of food, energy (calories) from processed carbohydrates, drinks, fast foods, snacks and condiments required when following a low carb diet.  This is usually followed by a focus on various ‘no or low carb’ vegetables, healthier fats (eg avocado, olive oil, nuts and seeds) and increased animal-based protein.

Of course, with only 6-8% of Australians reaching their recommended vegetable intake, a focus on eating more vegetables is positive.  However, it doesn’t necessarily mean that you would need to follow a low carb, high protein diet in order to achieve this.

Research has shown that a low carb, high protein diet is no more effective than enjoying a healthy, balanced eating pattern at achieving blood glucose levels improvement and body weight goals, especially in the long term.


Despite early desired outcomes to body weight and blood glucose levels, evidence suggests that in the long run results are similar to that of a healthy balanced diet.

Often when people stop losing weight, they start to lose confidence and can find it hard to stick to a diet.

When this is paired with the restrictions of very little carb-rich foods and/or other impacts such as gut problems or lacking key nutrients, many people stop the diet altogether.

Choosing a low carb, high protein diet can carry benefits such as increasing your vegetable intake but it can also be lacking in certain areas.

Many foods that may be restricted such as wholegrains and carb-containing vegetables including legumes, as well as dairy and fruit, provide a range of health-promoting nutrients.

These nutrients include fibre, vitamin C, folate, thiamine, magnesium and potassium.  Restriction of the above foods and or food groups, without supplementation and or monitoring, can result in poor health outcomes, eg, fatigue, hair loss and gut problems.

Some low carb, high protein diets may not distinguish between different types of fats and which to include.  This might mean you end up adding in foods, in particular red and white meat, which contain saturated fat. Eating a lot of saturated fat (ie solid fat at room temperature) may heighten your risk of blood vessel damage and heart disease.  It may also increase the possibility of insulin resistance in some people.

What is the latest research saying?

Overall, there is no strong evidence that a low carb, high protein diet will provide benefits to your health compared to alternative diets.

There also isn’t enough research to determine how safe this diet is in the long term.

As with health and nutrition, there really isn’t any ‘one size fits all’ approach.  While some people may find a low carb, high protein diet useful in managing their diabetes in the short term, there are a variety of alternative diets that can provide similar benefits.

With studies showing that 95-98% of dieters return to their pre-diet results after a longer period of time, the importance of an eating pattern that suits your needs and lifestyle is key.  People who wish to follow a low carb diet should do so in consultation with their diabetes health care team, including their Accredited Practising Dietitian.

Also, due to the increased risk of hypoglycaemia (very low blood glucose levels), checking your blood glucose levels regularly and speaking with your doctor about any adjustments to your diabetes medication is very important, particularly if you require insulin to manage your diabetes.

A low carb diet is not recommended for children, pregnant or breastfeeding women, unwell older people or people with certain medical conditions or histories.  Also, following a very low carbohydrate diet, such as a ketogenic diet, is not recommended due to the increased risk of ketones.

For more information, talk to your healthcare team or get in touch with a health professional at Diabetes Queensland on 1800 177 055.  You can also view the Diabetes Australia low carb position statement here, which includes references to various research studies that have been conducted.

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