KETO DIET VS LOW CARB DIET - WHAT’S THE DIFFERENCE?

Wondering if a low-carb diet or a keto diet is the best option for you? How do you know if you’re eating low carb or keto? What can each different diet do for you? Read on for answers, or if you just want to get clearer about where the line is between low-carb and keto. 

Knowing the difference between keto and a low carb

Put simply, the keto diet has specific rules because it causes specific chemical changes in the body - called ketosis. Low carb is a more general term used to describe our food choices – it isn’t precisely designed to get the body into ketosis (when the body uses fat for fuel, rather than glucose). 

A keto diet restricts carb intake to 20-50g per day and needs a high intake of healthy fats to work. It’s also necessary to keep protein intake moderate as too much can be stored as glucose – putting the brakes on your hard-earned ketosis. This process is known as gluconeogenesis. (1) 

On a low carb diet, up to 100g carbs per day are allowed, and there’s no guidance on how much protein or fat you should be eating. In short, eating low carb is a lot looser and less scientific than following a keto diet.

  

What’s a low carb diet?        

Grains, starchy vegetables and fruit, foods with added sugar and most alcohol are limited on low carb diets. Basically, as long as your carbs are under 100g then you’re on a low carb-diet – even if you’re not meticulously measuring your carbohydrate intake. Then there are the diets with specific rules that also fall into the low carb category – including a keto diet.

Some specific low-carb diets include:   

  • Low-carb Paleo – Based on paleo foods while keeping carbs under 100g.
  • The Atkins diet – A low carb eating plan with four different phases.
  • Zero-carb – Eating food almost exclusively from the animal kingdom.
  • The Dukan diet – A high protein, low fat, low carb diet created by Pierre Dukan.
  • The South Beach diet – Eating foods on a low glycaemic index, unsaturated fats and lean protein. 

What’s a keto diet?

A keto diet is a type of low carb, high fat diet. It’s named after the state of ketosis that body goes into when it switches from running on glucose to running on fat. This is achieved by focussing on a daily ratio of 70 – 75% fat, 20% protein, and 5 - 10% carbs. A ketogenic diet can steady a person’s blood sugar and insulin levels, which often results in weight loss and other health benefits. (2)    

In ketosis, fat is changed into an energy source called ketones. This means that the body isn’t reliant on glucose for fuel which can cause blood sugar highs and lows, and therefore insulin highs and lows too. Eventually, the insulin response can get tired, and this can lead to weight gain and health problems, including the risk of Type 2 diabetes. (3)  

Ketones - What are they?

Once you’ve been on a keto diet for anywhere between a few days to a couple of weeks, your body will be shifting into ketosis and producing a higher amount of ketones. Ketones are chemicals that are produced when fat is broken down – they can then be used as energy.

Every cell in the body can produce the energy molecule known as Adenosine Triphosphate (ATP), from either glucose or ketones. However, ketones make this process more efficient and produces fewer free radicals than glucose – which means ketones as a fuel source can be both healthier and more sustainable. (4)

Can I measure my ketones? 

Once you’re in ketosis, you’ll probably start seeing and feeling some changes - rapid weight loss, a fruity smell to urine or breath and flu-like symptoms are all very common. After a few weeks, the side effects should fade, and the weight loss continue at a steadier pace.

Ketone levels in blood, urine and breath rise once the body is in ketosis. So if you want to know for sure you’re in ketosis, you can measure the concentration of ketones in your pee with a home keto-urine test. Simply pass a keto stick through your urine stream, and then watch it change colour. For best results, check your pee mid-stream.

It's very common to pass urine more often when you start eating keto. Some glucose is stored in the body as muscle glycogen and liver glycogen. When you reduce your carb intake this store is used up. As the glycogen is released so is the water that is chemically bound to it – therefore the body needs to pass more urine to get rid of that extra water.

This side-effect will also pass as the body adapts, and as water loss slows, the body’s ability to burn fat will speed up. Of course, staying hydrated is always important, but particularly so when you start a keto diet – adding some electrolytes in too will help keep your system in balance.

 

How can ketones improve my health?

Ketones may be able to lower neuroinflammation

The likelihood of neuroinflammation and developing neurodegenerative disease such Alzheimer’s and Parkinson’s has been reduced when eating a keto diet. (5) Epileptic seizures have also been found to be less often on keto diets. (6)  

Ketones may have the potential to increase muscle strength.

Ketones may help protect against muscle breakdown and age-related muscle loss due to their anti-catabolic properties. (7) Muscle regeneration following exercise may also be boosted by ketones. 

Ketones may improve brain health

In one study, ketone supplements in patients with cognitive impairments or Alzheimer’s experienced improved brain function and quality of life. (8) As we age, the brain becomes poorer at using glucose for fuel, but switching to ketones can help the brain use a more efficient energy supply thus improving overall cognitive health.

Ketones may act as antioxidants

Antioxidants are molecules that fight harmful free radicals, which are linked to multiple illnesses, including diabetes, heart disease and cancer. Being in ketosis can raise the level of the most powerful antioxidant in the body - called glutathione. Ketones led to a 50% decrease in markers of radiation-induced cell damage during a study where mice were exposed to radiation. (9)  

Ketones may steady our mood

Ketones can increase GABA which is a calming neurotransmitter, and decrease glutamate which is an excitatory neurotransmitter - low GABA levels have been linked to a range of mood disorders. The increase of GABA due to increased ketones may explain the overall improvements in mood that are often reported on a keto diet. (10) 

Ketones may balance hormones    

Increasing dietary fat has been shown to increase oestrogen levels in women, before and after menopause. One study noted that low fats diets reduced oestrogen levels, whereas high fat diets increased oestrogen. (11) While in men, testosterone could increase by 13% on a high fat diet and drop of 12% on a low fat diet. (12) 

Ketones may supress appetite and cravings

As the body shifts into ketosis, fat becomes the primary fuel source – explaining the weight loss that most people see. However, there may be a two-fold gain because ketones can also reduce cravings and suppress appetite. Hormones control our appetite, and two of the hormones that ketosis can effect are ghrelin and cholecystokinin (CCK) – making us feel hungry less often and feel full more quickly. (13)

Ketones may lower cholesterol

Despite keto diets having a high fat content, ‘good’ cholesterol (HDL) was shown to increase and ‘bad’ cholesterol (LDL) plus triglycerides were shown to decrease during a studied 24-week keto diet. (14)

There’s no shortage of evidence that ketosis can be a beneficial state for the body to be in; however, always check with your doctor before making serious changes to your diet or lifestyle, especially if you have a pre-existing condition. 

Low carb vs Keto Round Up

The key thing to remember is that the term ‘low carb’ is broadly used to describe foods, diet plans and general eating choices, whereas a ‘keto’ diet is 70 – 75% fat, 20% protein and 5 - 10% carbs and specifically designed to get the body into ketosis – otherwise known as fat-burning mode.

Similar benefits can be gained on a keto diet and a low carb diet, but a keto diet plans to raise the amount of ketones in the bloodstream, changing your body chemistry, the way your body fuels itself, and leading to achieve specific health benefits.

If you’d like more information, check out further articles and info at our knowledge hub on the Keto Collective site

References

  1. https://www.britannica.com/science/glycogenesis
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7480775/
  3. https://www.cdc.gov/diabetes/library/features/diabetes-causes.html
  4. https://pubmed.ncbi.nlm.nih.gov/12813917
  5. https://pubmed.ncbi.nlm.nih.gov/16940764/
  6. https://www.seizure-journal.com/article/S1059-1311(14)00067-3/fulltext
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556006/
  8. https://alz-journals.onlinelibrary.wiley.com/doi/abs/10.1002/alz.037961
  9. https://faseb.onlinelibrary.wiley.com/doi/abs/10.1096/fasebj.30.1_supplement.627.3
  10. https://pubmed.ncbi.nlm.nih.gov/9778572
  11. https://academic.oup.com/jn/article/135/12/2862/4669919
  12. https://pubmed.ncbi.nlm.nih.gov/8942407/
  13. https://pubmed.ncbi.nlm.nih.gov/25698989/
  14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716748/