The ketogenic diet is one of the most researched dietary approaches of the past decade, with peer-reviewed evidence supporting its effectiveness for weight loss, blood sugar control, epilepsy management, and metabolic health. But the keto diet is also uniquely unforgiving: unlike most diets where a bad day is just a bad day, eating 20 grams too many carbohydrates can knock you out of ketosis entirely and restart the adaptation process from scratch.
This is why getting your keto macros right is not optional — it is the foundation of everything. This guide explains exactly how to calculate your personal keto macro targets, what the ratios actually mean, how to hit them with real food, and how to troubleshoot when the approach isn't working.
Macronutrients — or "macros" — are the three categories of nutrients that provide calories: protein, fat, and carbohydrates. Every food you eat contains some combination of these three, and on the ketogenic diet, the ratio between them determines whether your body achieves and maintains ketosis.
Ketosis is a metabolic state in which the body shifts its primary fuel source from glucose (derived from carbohydrates) to ketones (derived from fat). This shift occurs when carbohydrate intake is sufficiently low that the liver begins producing ketone bodies from fatty acids as an alternative energy source. The benefits associated with ketosis — reduced hunger, steady energy, mental clarity, fat loss — depend on actually being in ketosis, which is why macro precision matters far more on keto than on most other diets.
The traditional ketogenic diet follows a specific macro ratio that has been refined through decades of clinical use. The standard ratio is:
It is important to understand that these percentages are targets for the ratio of macros, not absolute gram amounts. The actual grams you need depend on your total daily calorie intake, which in turn depends on your body size, activity level, age, and weight loss goals.
Your TDEE is the total number of calories your body burns each day. It is the starting point for all macro calculations. TDEE is calculated using the Mifflin-St Jeor equation (the most accurate formula currently available) and then multiplied by an activity factor.
Use our free calorie tracker to calculate your TDEE automatically. As a rough guide:
If weight loss is your goal, subtract 300–500 calories from your TDEE to create a moderate deficit. A 500-calorie daily deficit produces approximately 0.5 kg of fat loss per week — a rate that is both effective and sustainable without triggering significant muscle loss or metabolic adaptation.
Use our free macro tracker to log your daily intake and see exactly where you stand against your keto targets.
Open Macro Tracker →On the ketogenic diet, you track net carbohydrates, not total carbohydrates. Net carbs are calculated as:
Net Carbs = Total Carbs − Dietary Fibre − Sugar Alcohols
Dietary fibre is not digested and absorbed in the same way as regular carbohydrates, and does not raise blood glucose or interfere with ketosis. This means high-fibre vegetables like broccoli, spinach, and cauliflower — which appear high in total carbs — are actually very low in net carbs and can be eaten relatively freely on keto.
The standard ketogenic carb limit is 20–50g of net carbs per day. Most people reach ketosis reliably at or below 20g. Some metabolically flexible individuals can maintain ketosis up to 50g — but this varies considerably by person and requires testing with urine or blood ketone strips to confirm.
Protein is the most commonly miscalculated macro on keto, and getting it wrong in either direction causes problems:
The sweet spot for most people is 1.5–2.0g of protein per kg of body weight. For a 70 kg person, this means 105–140g of protein per day — which typically falls within the 20–25% of calories range specified by the standard keto ratio.
The standard ketogenic diet (SKD) is not the only approach. Several variations have been developed to accommodate different goals and lifestyles:
The classic approach: 70–75% fat, 20–25% protein, 5% carbs. Best for people who are sedentary to lightly active, focused primarily on weight loss or metabolic health, and not performing high-intensity exercise.
Same as SKD, but with 20–50g of fast-digesting carbohydrates consumed immediately before high-intensity exercise sessions. Designed for athletes and gym-goers who need glycogen for performance but want to maintain ketosis the rest of the time. The carbs are timed to be burned during the workout, preventing them from interrupting ketosis.
Follows strict keto for 5–6 days per week, with 1–2 days of higher carbohydrate intake (150–250g) to replenish muscle glycogen. Popular among strength athletes and bodybuilders who find that sustained keto impairs training performance over time. Requires more sophisticated understanding of carbohydrate timing and is not recommended for keto beginners.
A variation that increases protein to 30–35% of calories while reducing fat to 60–65%. Carbs remain at 5%. Favoured by people who want to preserve or build muscle while in a calorie deficit. The higher protein intake may slightly reduce the depth of ketosis for some individuals but generally does not prevent it entirely.
| Food | Fat per 100g | Net Carbs per 100g |
|---|---|---|
| Avocado | 15g | 1.8g |
| Olive oil | 100g | 0g |
| Butter | 81g | 0g |
| Cheddar cheese | 33g | 0.1g |
| Macadamia nuts | 76g | 5g |
| Coconut oil | 100g | 0g |
| Salmon (Atlantic) | 13g | 0g |
| Food | Protein per 100g | Net Carbs per 100g |
|---|---|---|
| Chicken breast | 31g | 0g |
| Beef (80% lean mince) | 17g | 0g |
| Eggs | 13g | 0.6g |
| Tuna (canned in water) | 25g | 0g |
| Pork belly | 9g | 0g |
| Greek yogurt (full fat) | 10g | 4g |
| Vegetable | Net Carbs per 100g | Notes |
|---|---|---|
| Spinach | 1.4g | Excellent micronutrient density |
| Broccoli | 4g | High fibre, very filling |
| Cauliflower | 3g | Versatile keto staple |
| Courgette (zucchini) | 2.1g | Great pasta substitute |
| Asparagus | 1.8g | Rich in folate |
| Bell pepper | 5g | Highest in vitamin C |
The majority of keto beginners experience what is commonly called the "keto flu" during the first 3–5 days of the diet. Symptoms include headache, fatigue, brain fog, irritability, nausea, muscle cramps, and difficulty sleeping. These symptoms are real but temporary, and they arise from two causes:
By the end of the second week, most people notice a dramatic improvement. Energy levels stabilise, hunger decreases noticeably, mental clarity improves, and the cravings for carbohydrates that were intense in week one begin to fade. This is the beginning of keto adaptation — the process by which the body becomes increasingly efficient at running on fat and ketones as its primary fuel source.
Full keto adaptation takes 4–8 weeks for most people. Athletic performance in high-intensity activities may be reduced during this period but typically returns to baseline — and often improves — after full adaptation.
Many foods marketed as keto-friendly contain significantly more carbohydrates than expected. Always check the nutrition label — and specifically the net carbs — rather than trusting packaging claims. Common culprits include: protein bars and shakes (often 10–20g net carbs), tomato-based sauces (8–12g net carbs per serving), salad dressings (6–10g per serving), and many nuts (cashews and pistachios are surprisingly high).
As described above, excess protein can theoretically be converted to glucose. While this effect is smaller than often claimed, people who are eating 3g+ of protein per kg of body weight and struggling to maintain ketosis should consider moderating protein intake and replacing those calories with fat instead.
Many people combine keto with a very aggressive calorie restriction (under 1,200 calories per day). While fat loss may be rapid initially, this approach typically leads to significant muscle loss, metabolic adaptation, and unsustainable hunger. A moderate deficit of 300–500 calories below TDEE is more effective over the medium term.
The elimination of grains, most fruits, and many vegetables on strict keto creates real risk of micronutrient deficiencies — particularly in magnesium, potassium, thiamine, folate, and vitamin C. Prioritising nutrient-dense keto foods (leafy greens, avocado, nuts, organ meats, fatty fish) and considering a comprehensive multivitamin is advisable for long-term keto practitioners.
Ketosis is a metabolic state that has been both oversimplified and mystified in popular health culture. Understanding the actual biochemistry of ketosis — what triggers it, what it feels like, and what it does to body composition and metabolic health — provides a more accurate foundation for deciding whether a ketogenic dietary approach is appropriate for your goals.
When carbohydrate intake is restricted below approximately 20–50g per day and glycogen stores are depleted, the liver begins converting fatty acids into ketone bodies — primarily beta-hydroxybutyrate (BHB), acetoacetate, and acetone. These ketone bodies are released into the bloodstream and taken up by cells throughout the body, including neurons in the brain, as an alternative to glucose. This metabolic switch from glucose to ketones as the primary brain fuel is the defining characteristic of nutritional ketosis and distinguishes it from the normal fat-burning that occurs during moderate exercise or overnight fasting.
Nutritional ketosis is defined by blood ketone levels of 0.5–3.0 mmol/L. Levels above this range (above 10 mmol/L) constitute diabetic ketoacidosis — a dangerous medical condition that occurs in type 1 diabetics and is not achievable in healthy individuals through diet alone. Nutritional ketosis is safe for most healthy adults; the concern about ketoacidosis is medically distinct from the ketosis induced by a ketogenic diet.
The transition from glucose to ketone metabolism — "keto adaptation" or "fat adaptation" — typically takes 2–6 weeks and is associated with a well-documented period of reduced performance and subjective wellbeing known colloquially as the "keto flu." Symptoms include fatigue, headaches, brain fog, irritability, muscle cramps, and reduced exercise capacity. These symptoms result primarily from electrolyte imbalances (sodium, potassium, and magnesium are excreted more rapidly when insulin levels are low and glycogen is depleted) rather than from ketosis itself, and can be substantially reduced by adequate electrolyte supplementation — particularly sodium (3,000–5,000mg per day) and potassium (3,500–4,700mg per day) — during the adaptation period.
After full keto adaptation, most people report normalisation of energy, improved mental clarity, and stable hunger — particularly in the mid-afternoon period when blood glucose dips are common on carbohydrate-based diets. Exercise performance in endurance activities generally recovers to pre-keto levels after full adaptation; high-intensity exercise performance may remain somewhat reduced due to the lower power output achievable from fat oxidation compared to glucose oxidation.
The ketogenic diet is not a single protocol but a family of related approaches that differ in how strictly and continuously carbohydrate restriction is maintained. Understanding these variations allows for selection of the approach most compatible with individual lifestyle, preferences, and goals.
The standard ketogenic diet maintains carbohydrate restriction continuously, typically targeting 20–50g of net carbs per day seven days per week. This approach achieves the deepest and most consistent ketosis but is the most restrictive in terms of food choices and social flexibility. SKD is the most widely researched variation and the approach used in most clinical studies examining ketogenic diet effects on epilepsy, weight loss, and metabolic health. It is best suited to people whose primary goals are therapeutic (epilepsy management, insulin resistance treatment) or who find consistent restriction easier than managing periodic carbohydrate reintroduction.
The cyclical ketogenic diet alternates periods of strict ketogenic eating (typically 5–6 days) with planned high-carbohydrate "refeed" days (typically 1–2 days per week). The rationale for this approach is that periodic carbohydrate refeeding replenishes muscle glycogen, supports high-intensity exercise performance, provides metabolic flexibility, and improves long-term dietary adherence by providing regular scheduled flexibility. CKD is popular among recreational athletes who follow a ketogenic approach for body composition benefits but need glycogen availability for higher-intensity training sessions.
The targeted ketogenic diet allows small amounts of carbohydrates (typically 25–50g of fast-absorbing carbs) immediately before or after exercise — timed to fuel performance without disrupting overall ketosis significantly. The carbohydrates consumed in the peri-workout window are rapidly metabolised during exercise and do not cause meaningful ketosis interruption. TKD is the most practical approach for people who train at high intensity regularly (CrossFit, HIIT, competitive sport) and find their performance compromised by continuous strict ketogenic eating.
Women's hormonal physiology creates specific considerations for ketogenic dietary approaches that are important to understand before committing to long-term carbohydrate restriction. The evidence base for keto in women is growing but remains less comprehensive than in men.
Low-carbohydrate diets have been associated with reduced conversion of T4 (inactive thyroid hormone) to T3 (active thyroid hormone) in some studies. Since T3 is the metabolically active form that regulates metabolic rate, this conversion reduction could theoretically reduce TDEE — a concern for women managing weight. The clinical significance of this effect in healthy individuals is debated; it appears more pronounced in very low-calorie ketogenic diets than in well-formulated, adequate-calorie ketogenic diets. Women with diagnosed or suspected thyroid conditions should discuss dietary carbohydrate restriction with their healthcare provider before beginning a ketogenic diet.
Some women report changes to their menstrual cycle when following a ketogenic diet, particularly in the initial adaptation period and when the diet is combined with significant calorie restriction. This mirrors the broader hormonal sensitivity to energy availability discussed in the BMI and healthy weight articles. Women who experience persistent menstrual irregularity on a ketogenic diet should consider whether total calorie intake is adequate (keto can reduce appetite significantly, sometimes to below appropriate levels), whether electrolyte intake is sufficient, and whether the carbohydrate restriction is more aggressive than necessary for their goals.
Translating macronutrient targets into actual food choices is the practical challenge of implementing a ketogenic diet. The following framework covers the major food categories and their keto compatibility.
Meat, poultry, and fish (all unprocessed cuts); eggs (all preparations); most cheeses; heavy cream and full-fat dairy; non-starchy vegetables (leafy greens, broccoli, cauliflower, zucchini, asparagus, cucumber, celery, spinach, kale); avocado; olives; nuts and seeds (macadamia, walnuts, almonds, chia seeds — in moderation due to calorie density); olive oil, coconut oil, avocado oil, and butter. These foods form the foundation of a well-formulated ketogenic diet and can be consumed in quantities consistent with your calorie targets without exceeding carbohydrate limits.
Berries (strawberries, raspberries, and blackberries are the lowest-carb fruits at 5–6g net carbs per 100g); nuts (particularly cashews and pistachios, which are higher in carbs than other nuts); full-fat yoghurt and cottage cheese (contain some lactose, which contributes carbohydrates); tomatoes and peppers (moderate carb vegetables); dark chocolate (70%+ cacao, 1–2 squares only). These foods can be included in a ketogenic diet but require tracking to ensure total carbohydrate targets are maintained.
All grains and grain products (bread, pasta, rice, oats, corn); most fruit (high sugar content); starchy vegetables (potatoes, sweet potatoes, carrots in large quantities, parsnips); legumes (beans, lentils, chickpeas — high in carbohydrates despite their protein content); sugar and sweetened foods (soft drinks, juice, candy, most desserts); most sauces and condiments containing sugar (ketchup, teriyaki sauce, many barbecue sauces). Eliminating these food categories is the primary change that brings carbohydrate intake below the ketogenic threshold.
Verifying that you have achieved nutritional ketosis is possible through three main measurement methods, each with different accuracy, convenience, and cost profiles.
Urine ketone strips are the most affordable option (approximately $10–20 for 100 strips) and detect acetoacetate in urine. They are most useful in the first few weeks of a ketogenic diet when acetoacetate excretion is high. Over time, as keto adaptation occurs and the body becomes more efficient at utilising ketones, urine ketone excretion decreases even as blood ketone levels remain elevated — making urine strips less reliable as a measure of sustained ketosis in fully adapted individuals.
Blood ketone meters (approximately $30–60 for the device, plus $1–3 per test strip) measure beta-hydroxybutyrate (BHB) directly in the blood and are the most accurate method for determining ketone levels. They are used in clinical research and by serious practitioners. Nutritional ketosis is confirmed at readings of 0.5 mmol/L or above; levels of 1.0–3.0 mmol/L represent optimal nutritional ketosis for most purposes.
Breath acetone monitors (approximately $150–300 for the device) measure acetone in exhaled breath, which correlates with blood BHB levels. They require no test strips and provide ongoing measurement capability at a fixed one-time cost, making them cost-effective for people who plan to monitor ketosis long-term. Accuracy is somewhat lower than blood testing but superior to urine strips for established ketosis.
The ketogenic diet is not universally superior to other dietary approaches — but it does have specific populations for whom the evidence is particularly strong: