With each New Year another eating plan hits the headlines as the best and most effective way to lose weight.
The ketogenic diet has already been through its paces and has proven to be remarkably successful, however, as is often the case, it doesn’t always work for everyone.
We always take an evidence-based approach and aim to provide you with actionable knowledge and tips to help you on your journey to optimal health. In this article we discuss what a ketogenic diet is, how to follow it properly and why some people may not benefit from it at all.
Very low-carbohydrate diets, or ketogenic diets, have been around for quite some time. As far back as the 1920s medical experts used the ketogenic diet to treat epilepsy, which in some cases removed the need for medication entirely.
Evidence gathered over the last decade or so has shown ketogenic diets have great therapeutic value in many health conditions such as diabetes, cancer, polycystic ovary syndrome, neurological disease and cardiovascular disease risk factors. (1) However, the most common appeal of this way of eating is to people looking for a quick and easy way to lose weight.
What is a keto diet?
The ketogenic diet is characterised by a reduction in carbohydrates (usually as little as 20g-30g a day), coupled with higher levels of protein and fat.
It provides sufficient protein for growth but insufficient amounts of carbohydrates for the energy needs of the body.
Unlike other low-carb diets focused on protein, a ketogenic eating plan centres on fat, which supplies as much as 90% of daily calories.
If the ketogenic diet is followed sensibly it should be a highly nutritious diet, based around whole unprocessed foods, and fibre rich vegetables.
How does it work?
The aim of the ketogenic diet is to push your body into using an alternative source of energy for fuel, resulting in a state of ketosis.
Ketosis is the process by which your body uses fat for energy instead of relying on glucose (sugar) gained from breaking down carbohydrates.
Examples of carbohydrates
- Potatoes – white and sweet
- Pasta
- Bread
- Corn
- Cereals
- Butternut squash
- Grains – rice, wheat, bulgur, millet, buckwheat, oatmeal
- Légumes – beans, chickpeas, lentils, peas, peanuts
- Vegetables
- Fruits
An effective ketogenic diet relies on ketone bodies, a type of fuel the liver produces from stored fat. For this to happen, insulin levels in the body have to be low. (2) Preventing surges in insulin requires an absence of carbohydrates, or at least less than 50g a day.
Insulin activates key enzymes in biochemical pathways that store energy derived from carbohydrates; the resulting reduced insulin levels alter how the body generates energy, leading to a reduction in the formation of fat (lipogenesis) and fat accumulation.
Sticking to foods that don’t raise insulin levels, gives your body the opportunity to go into ketosis and burn body fat – this usually takes a few days.
It should be noted that eating too much protein can interfere with ketosis because the body can utilise excess protein to make glucose, a process known as gluconeogenesis (GNG).
- The science behind ketosis
When there is a scarcity of dietary carbohydrates, the body’s glucose reserves drop below a level that allows it to produce the type of fuel needed for the brain and central nervous system to function.
After 3-4 days the central nervous system needs an alternative energy source, derived from the overproduction of a chemical called acetyl-CoA. This results in the production of ketone bodies, (acetoacetate (AcAc), β-hydroxybutyric acid (BHB) and acetone).
This process is called ketogenesis and occurs principally in the mitochondria (the energy factories) in the liver. Although the liver produces ketone bodies it cannot utilise them without a specific enzyme known as 3-ketoacyl CoA transferase. (3)
Benefits of a ketogenic diet
When your body switches from burning glucose to burning ketones, you might expect some positive results such as:
- Rapid weight loss
- Reduction in fat production
- More efficient metabolism
- Reduced appetite – ketone bodies are thought to suppress the appetite
- Feeling fuller quicker
- Increased muscle mass
- Improved blood pressure
- Reduced inflammation
- Increased energy
- Lowered risk for heart disease
- Improved blood sugar balance
- Potential reduction of epileptic seizures
- Improved insulin signalling
- Reduction in oxidative stress
In a meta-analysis of 13 different randomised controlled trials, the findings of five of these revealed significant weight loss from a ketogenic diet. It was also found that individuals assigned to a very low-carb keto diet achieved a greater weight loss than those assigned to a low-fat diet in the long term. (5)
Other research has identified the keto diet significantly raises levels of adiponectin, a protein involved in fat metabolism and blood sugar regulation. (6)
What can you eat?
For this eating plan to be successful it is essential to choose nutritious, whole foods and drink plenty of fluids. A difficulty with this way of eating is having enough fat without too much protein.
A ketogenic diet usually consists of:
- High fat – at least 75%-90% of your daily calorie intake
- Moderate protein – around 20-30% of your daily calorie intake
- Very low carbohydrate – between 5 and 10% of your daily calorie intake and no more than 50g per day. Some people stay below 30g per day to maximise ketosis effects
For an individual on a weight loss diet of around 1,500 calories a day, this would mean eating around 125g fat, 70g protein and 30g carbs. This ratio is dependent on each individual’s age, height, weight, activity levels and their particular needs.
To meet the daily fat requirements of the ketogenic diet you should eat fat at every meal, although you should avoid highly processed fats and oils.
Examples of preferred fats include:
- Coconut oil
- Olive oil
- MCT oil
- Flaxseed oil
- Walnut oil
- Duck fat
- Goose fat
- Almond oil
- Butter
- Lard
Fruits, veggies and the carbohydrate count
This is where you need to pay close attention to the amount you eat, particularly with fruits which are much higher in carbs. Certain fruits such as berries can be included in small portions.
It is important to remember that vegetables are vital because they are nutrient rich, so they should be eaten at each meal. Choosing lower carbohydrate veggies means you can benefit from the extra fibre and add more to your plate.
Be mindful of starchy root vegetables – these can increase your carbohydrate levels and potentially sabotage ketosis.
As an example, 100g potato contains 17g carbohydrates whereas 100g of aubergine contains just 6g.
Avoid the following or count portion sizes very carefully:
- Potatoes
- Corn
- Peas
- Parsnips
- Butternut squash
- Sweet potatoes
- Beetroot
- Cassava
- Plantains
- Yams
- Beans
Examples of low-carb veggies (approx. 1 cup – unless stated otherwise):
| » Asparagus | 180g = 8g carbs |
| » Aubergine | 100g = 6g carbs |
| » Avocados | 150g = 13g carbs |
| » Bell peppers | 149g = 9g carbs |
| » Broccoli | 91g = 6g carbs |
| » Brussel sprouts | 78g = 6g carbs |
| » Carrot (1 medium) | 61g = 5.8g carbs |
| » Cauliflower | 100g = 5g carbs |
| » Celery | 101g = 3g carbs |
| » Courgette | 124g = 4g carbs |
| » Cucumbers | 104g = 4g carbs |
| » Garlic | 3g = 1g carbs |
| » Green beans | 125g = 10g carbs |
| » Kale | 67g = 6g carbs |
| » Lambs lettuce | 100g = 2g carbs |
| » Lettuce | 47g = 2g carbs |
| » Mushrooms | 70g = 2g carbs |
| » Onion | 115g = 11g carbs |
| » Pak Choy | 70g = 1.5g carbs |
| » Rocket | 100g = 3.65g carbs |
| » Spinach | 180g = 7g carbs |
| » Tomato | 150g = 5.88g carbs |
| Carbohydrate count of various fruits: | |
| » Strawberries | 1 cup = 11.67g carbs |
| » Blackberries | 1 cup = 13.84g carbs |
| » Blueberries | 1 cup = 21.01g carbs |
| » Apple | 1 medium = 19.06g carbs |
| » Pear | 1 medium = 25.66g carbs |
| » Orange | 1 medium = 15.39g carbs |
| » Kiwi | 1 fruit = 11.14g carbs |
| » Grapes | 1 cup = 28.96g carbs |
Protein allowances
Typical sources of protein include meat, fish, dairy, beans, nuts, seeds, eggs, tofu, chickpeas and lentils. Your protein intake should be fairly moderate – as a rough guideline, aim for around 40-50g per day if you are a woman and 50-60g a day if you are a man.
If you are struggling to lose weight even though you are keeping an eye on your carbohydrate intake, you may be eating too much protein. Perhaps you are including too much cheese or snacking on too many nuts, both of which are significantly high in protein.
Eggs are great keto foods as they are low in carbs and moderate sources of protein, plus they are filling so make an ideal snack. An average egg contains 6.29g protein and 0.38g carbohydrates.
It is highly recommended to include oily fish in your keto eating plan. Fish such as salmon, mackerel, fresh tuna, trout and herring are rich sources of omega-3 fatty acids. This type of fat is particularly beneficial for brain and heart health as well as hormone balance.
Dairy products provide good levels of fat so are a real staple on a ketogenic diet.
Cream is preferable to milk for adding to tea or coffee, as it has a lower carbohydrate count.
Be wary of low fat products which usually have high sugar/carbohydrate counts. Full fat cheese and yoghurt are good inclusions for a keto diet, but also contain significant amounts of protein and some carbs.
Choose grass fed butter over other butters because it has higher levels of omega-3 fatty acids and vitamins A, D, E and K. Margarine is a highly processed fat and should be avoided.
We must not forget nuts and seeds, high in fat, low in carbohydrates and have moderate levels of protein – a perfect keto food. They are also a great source of fibre and important minerals such as magnesium and selenium. But some nuts, such as cashews, have higher carbohydrate content than others such as Brazil nuts, macadamias, walnuts, almonds, hazelnuts and flax seeds.
Make the most of high fat nut butters – spread on a celery stick these make delicious snacks. Nut milks like unsweetened almond milk are a useful substitute for cow’s milk if you don’t enjoy cream in your coffee or tea.
Does the keto diet suit everyone?
Liver enzymes play a key role in ketogenesis and scientists have discovered some people may be deficient in the ketogenesis enzyme in the liver (HMG-CoA lyase). This means they have a block in the metabolic pathway associated with beta oxidation of fatty acids and therefore cannot produce fat burning ketone bodies, so it may be impossible to switch from glucose burning to fat burning. (6) Someone with this genetic disadvantage might not respond well to a ketogenic diet and it could potentially make them feel extremely unwell.
In a normal healthy person the body will adapt to this shortfall, but if you have health concerns you should consult with your GP before approaching this type of diet.
Adverse effects
During the initial stages of ketosis, some people experience uncomfortable symptoms, commonly called ‘keto flu’, thought to be a result of glucose withdrawal. It doesn’t happen to everyone, but you might find you feel sluggish and irritable with an upset stomach, headaches, difficulty sleeping and nausea.
This should only last for around a week or two and should be managed by making sure you are adequately hydrated by drinking plenty of water, particularly in the morning and between meals.
It is also important to ensure you maintain your electrolyte balance by adding around 2 tsp salt to your meals each day as well as topping up the trace minerals in your diet by including celery, cucumber, sea vegetables, pickles and green leafy vegetables.
Exercise is essential too and it may be helpful to supplement with some probiotics, especially if you find you are becoming constipated.
If you continue to feel unwell, this type of diet may not be for you and you should start to increase your carbohydrates.
Can the keto diet be sustained long term?
Recent research suggests that the ketogenic is best used over brief periods (approximately 20 days), interspersed with a longer six month period of maintenance with the Mediterranean diet. (4) This approach has led to successful long term weight loss, with the added bonus of improvements in health risk factors and without any weight gain.
Takeaway
Don’t be disheartened if the ketogenic diet doesn’t work for you, we are all genetically different and a successful nutrition plan has to be tailored to the individual.
If you would like help losing weight, why not take advantage of a complimentary consultation with one of our qualified Personalised Health practitioners here at Amchara.
We believe that sharing knowledge and experience is an important part of achieving optimal health.
Have you tried a keto diet?
We would love to hear from you, get in touch.
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