You might have heard of the ketogenic diet—maybe from a friend, a podcast, or social media. But what is it really?
Is it just another trend?
Or could it be a way to support your energy, brain health, mood, and metabolism?
The ketogenic diet is more than a low-carb plan for weight loss. It’s a shift in how your body fuels itself. And for some people, it can make a meaningful difference to how they feel—physically and mentally.
Let’s break it down in a way that’s clear, practical, and based on research.
What is the ketogenic diet?
The ketogenic diet (often called keto) is a way of eating that’s high in fat, very low in carbohydrates, and moderate in protein.
The goal is to switch your body from using sugar (glucose) as its main fuel to using fat.
When you eat very few carbs, your body starts making ketones from fat—both the fat you eat and the fat you store. These ketones fuel your brain, muscles, and other organs.
This state is called ketosis.
Most people on keto eat:
- 60–75% of their calories from fat
- 15–30% from protein
- 5–10% from carbohydrates (about 20–50g per day)
This might sound restrictive, but it can offer surprising benefits, especially for people struggling with blood sugar problems, energy dips, or cognitive concerns.
How can this benefit your health?
Let’s look at what the science says—beyond weight loss.
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Sharper thinking and memory support
Your brain is energy-hungry. As you age, it becomes less efficient at using glucose.
Ketones give your brain a steady, alternative fuel source—one it often prefers.
- A 2021 randomised controlled trial found that people with mild cognitive impairment improved memory and attention after 12 weeks on a ketogenic diet (Phillips et al., 2021, Neurobiology of Aging).
- Studies also show that ketones can reduce oxidative stress and inflammation in the brain (Cunnane et al., 2020, Frontiers in Aging Neuroscience).
Do you notice more brain fog or forgetfulness than you used to?
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Better mood and mental wellbeing
Many people experience more stable moods and fewer low-energy slumps on keto.
This could be because:
- Blood sugar levels remain more stable
- Inflammation decreases
- Mitochondrial function (your cells’ energy production) improves
A 2022 study found that adults with depression had fewer symptoms after following a ketogenic diet for several weeks (Brietzke et al., 2022, Journal of Affective Disorders).
Some people also report reduced anxiety, more balanced emotions, and improved sleep.
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More stable energy and fewer crashes
Ever feel wiped out after lunch or desperately need caffeine by 3pm?
Switching to fat as a main fuel can help avoid energy spikes and dips.
Once you’re adapted, your body can tap into fat stores to fuel your day—without constant snacking.
Clinical studies have found that keto improves:
- Insulin sensitivity
- Blood glucose control
- HbA1c levels in type 2 diabetes (Saslow et al., 2017, JMIR Diabetes)
This may help if you’ve been told you’re prediabetic or have metabolic syndrome.
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Reduced inflammation and chronic pain
Chronic inflammation is behind many health concerns—joint pain, digestive issues, headaches, skin problems, and fatigue.
A 2020 study on people with rheumatoid arthritis showed lower inflammatory markers and pain scores after following a ketogenic diet (Pérez-Guisado & Muñoz-Serrano, 2020, Journal of Clinical Rheumatology).
Many people notice improvements in swelling, stiffness, or even post-exercise recovery.
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Fewer cravings and better appetite control
Keto may help regulate your hunger hormones—especially ghrelin and leptin.
You might find you naturally eat less or snack less often, without forcing it.
A 2013 review found that ketones themselves may reduce hunger and food obsession (Sumithran et al., 2013, Obesity Reviews).
If you’ve struggled with cravings or emotional eating, this shift in fuel source may support more stable eating habits.
Who should avoid the keto diet?
The ketogenic diet isn’t suitable for everyone. Avoid or seek medical advice if you have:
- Type 1 diabetes
- A history of disordered eating
- Gallbladder removal without support for fat digestion
- Liver or pancreatic disease
- Very low body weight or nutrient deficiencies
- Pregnancy or breastfeeding (unless under professional guidance)
Always speak to a qualified practitioner before starting keto if you take medication, especially for blood sugar or blood pressure.
Is keto right for you?
If you’re dealing with low energy, brain fog, blood sugar issues, cravings, or mood swings, the ketogenic diet may be worth exploring.
You don’t have to fit a particular mould to try it. People across the dietary spectrum—from vegan to carnivore and everything in between—can adapt their diet to follow a well-formulated ketogenic approach.
You can do keto using:
- Plant-based fats like olive oil, avocado, nuts, seeds, and coconut
- Animal-based options like oily fish, eggs, and full-fat dairy (if tolerated)
- Low-carb, nutrient-dense vegetables and fermented foods
Keto can also be combined with anti-inflammatory, Mediterranean, or gut-supportive frameworks. It’s not one-size-fits-all—and it doesn’t have to be extreme.
How long should you follow a keto diet?
This depends on your goals, your health history, and how your body responds.
Some people use keto short-term to restore metabolic health, regulate appetite, or reduce inflammation. Others stay on it for years to manage chronic conditions or maintain cognitive benefits.
Is it safe long-term?
A 2021 review of long-term ketogenic diet use found no significant safety concerns in adults when the diet was appropriately managed and nutrient intake was monitored (Paoli et al., 2021, Nutrition).
Another follow-up study in people with type 2 diabetes showed that after 2 years on a ketogenic diet, participants maintained improved blood sugar control, reduced medication use, and saw no adverse effects on kidney or liver function (Athinarayanan et al., 2020, Frontiers in Endocrinology).
The key is personalisation, nutrient adequacy, and ongoing support.
References:
Phillips, M.C., Krikorian, R., Tong, M. et al., 2021. Dietary ketosis enhances memory in mild cognitive impairment: results of a randomized clinical trial. Neurobiology of Aging, 98, pp.111–119.
Calabrese, L., Frase, R. & Ghaloo, M., 2024. Complete remission of depression and anxiety using a ketogenic diet: case series. Frontiers in Nutrition, 11:1396685.
Athinarayanan, S.J., Adams, R.N., Hallberg, S.J. et al., 2020. Long‑term effects of a continuous remote care intervention including nutritional ketosis for the management of type 2 diabetes: 2‑year outcomes. Frontiers in Endocrinology, published online.
Paoli, A., 2021. Ketogenic diets and de novo lipogenesis: narrative review. Nutrients, 17(4):663.
Brietzke, E., McIntyre, R.S., Silva, R.H. et al., 2022. The ketogenic diet as a treatment for mood disorders: mechanisms and outcomes. Journal of Affective Disorders, forthcoming / online.
Frontiers in Nutrition, 2022. Low‑carbohydrate ketogenic diets reduce cardiovascular risk factors in obese/overweight patients with type 2 diabetes: meta‑analysis of RCTs. Frontiers in Nutrition, 9:1092031.
Frontiers in Nutrition, 2021. Review of ketogenic diets and chronic disease: weighing benefits and risks. Frontiers in Nutrition, 702802.
Frontiers in Neuroscience, 2022. Does neuroinflammation underlie the cognitive changes observed in ketosis diets? Frontiers in Neuroscience, article on neuroinflammation in MCI/AD.
Fortier, M., Castellano, C.-A., St‑Pierre, V. et al., 2021. A ketogenic drink improves brain energy and some measures of cognition in mild cognitive impairment: a 6‑month RCT. Alzheimer’s & Dementia, 17(3), pp.543–552.
Krikorian, R., Shidler, M.D., D’Angelo, K. et al., 2012. Dietary ketosis enhances memory in mild cognitive impairment. Neurobiology of Aging, 33(2), pp.425.e19–425.e27.