Keto macros in plain English: under 30g net carbs, 60-75% fat, 20-25% protein
Ketosis is a metabolic state where your liver produces ketones from fat as primary fuel instead of glucose from carbohydrates. This switch happens when carbohydrate intake drops low enough — typically under 30g net carbs per day — that glycogen stores are depleted. Net carbs = total carbs minus fiber minus sugar alcohols. A 5g net-carb diet isn't required; most people enter and maintain ketosis comfortably at 20-30g net carbs.
The most common keto mistake isn't carb counting — it's over-eating protein. Excess protein undergoes gluconeogenesis (the liver converts amino acids to glucose), which raises blood sugar and can kick you out of ketosis. The target: 0.6-0.8g protein per pound of lean body mass, not total body weight. A 200-lb person with 180 lb lean mass targets 108-144g protein, not 200g. More protein than this can stall ketosis without adding muscle.
The 7-day starter framework: 210g weekly carb budget
A week of keto at 30g/day = 210g total net carb budget. Spend it strategically. The lowest-carb vegetables give the most food volume per carb gram:
- Spinach, kale, arugula, romaine: 0.5-1g net carbs per cup. Eat freely.
- Broccoli, cauliflower: 3-4g net carbs per cup cooked. Core keto vegetables.
- Zucchini, cucumber, celery: 2-3g per cup. Good fillers.
- Bell peppers: 4-5g per ½ cup. Moderate — don't overdo.
- Nuts: 3-6g net carbs per oz (almonds, walnuts, macadamias are lowest).
- Berries: 5-6g per ½ cup. The only permitted fruit in meaningful quantity.
- Avocado: 2g net carbs per half. One of the best foods on keto — fat + fiber + potassium.
Eliminate: all grains (bread, pasta, rice, oats), all legumes (beans, lentils, chickpeas), all starchy vegetables (potato, corn, peas), most fruit, all sugar, most sauces and condiments (ketchup, teriyaki, BBQ sauce). Read labels — "low fat" products often substitute sugar for fat.
Quality fat sources: what to eat and why it matters
Fat provides 60-75% of your keto calories. This isn't a license to eat any fat indiscriminately — quality and type matter:
- Extra-virgin olive oil: monounsaturated fat, anti-inflammatory. Use for cooking and salads. 120 cal/tbsp.
- Avocado oil: neutral flavor, high smoke point (520°F), excellent for high-heat cooking. 120 cal/tbsp.
- Butter, ghee: saturated fat for sautéing and finishing. Ghee has a higher smoke point (485°F) and is casein-free for dairy-sensitive people.
- Coconut oil, MCT oil: medium-chain triglycerides are converted to ketones more rapidly than other fats — a performance-level tool for athletes or those wanting faster ketone elevation. MCT oil can cause digestive distress at high doses; start with 1 tsp and build up.
- Fatty meat (ribeye, salmon, chicken thighs, pork belly): fat + protein combined. Ribeye at 80/20 fat-to-protein ratio is the most keto-friendly beef cut. Salmon provides omega-3 fat and protein together.
- Full-fat cheese: near-zero carb, high fat, good protein. Cheddar, brie, gouda, cream cheese all work. Aged cheeses typically have 0g carbs.
- Nuts and seeds: macadamia nuts (lowest carb), walnuts (best omega-3), almonds, pecans. Cashews are the highest-carb nut — limit.
The keto flu: what it is and how to prevent it
Days 2-5 of keto, many people experience headaches, fatigue, brain fog, muscle cramps, and irritability — the "keto flu." This is not a sign that keto is failing. It's caused by electrolyte loss: as the body burns through glycogen (stored carbohydrate), it also sheds significant water and sodium. The kidneys then excrete additional potassium and magnesium in response to the lowered insulin levels.
Prevention protocol: add 3-5g extra sodium per day (bone broth, salted food, electrolyte packets like LMNT or Liquid IV). Supplement 300-400mg magnesium glycinate before bed (helps with cramps and sleep). Aim for 3,500mg potassium/day from food (avocado, leafy greens, salmon). Drink water — at least 2-3 liters per day. The flu passes in 3-7 days. If symptoms persist past 10 days, your electrolytes are still out of balance.
Sample day at 1,700 calories / 22g net carbs
Breakfast (450 cal, 5g net carbs): 2 large eggs scrambled in 1 tbsp butter + 2 slices bacon + ½ avocado with salt.
Lunch (520 cal, 8g net carbs): 6 oz grilled chicken thigh + 2 cups baby spinach + 2 tbsp olive oil vinaigrette + 1 oz almonds + 10 cherry tomatoes.
Dinner (650 cal, 6g net carbs): 8 oz ribeye steak + 1 cup cauliflower mash (cauliflower + butter + cream + salt) + 1 cup steamed broccoli with butter.
Snack (80 cal, 3g net carbs): ½ cup strawberries + 2 tbsp heavy cream.
Total: 1,700 cal, ~105g protein, 22g net carbs, 125g fat. Adjust protein up or down based on body weight and activity level.
Weekly grocery list for 1 keto adult ($80-100/week)
Proteins: 2 lb chicken thighs ($5), 1 lb 80/20 ground beef ($6), 1 lb bacon ($7), 1 lb salmon ($10), 1 dozen eggs ($4), 8 oz cheddar cheese ($4).
Vegetables: 2 lb mixed leafy greens ($5), 1 head broccoli ($2), 1 head cauliflower ($3), 1 head cabbage ($2), 4 avocados ($6).
Fats/dairy: 1 bottle olive oil ($8, lasts 3+ weeks), 1 lb butter ($5), 8 oz mixed nuts ($8), 1 pint heavy cream ($4).
Extras: 1 pint berries ($5), bone broth (for electrolytes, $4), seasonings.
Total: approximately $88. Add $15-20 for grass-fed/organic upgrades. A family of 2 on keto: $150-180/week.
Keto meal prep: Sunday in 90 minutes
The same batch-cook logic that works for general meal planning applies to keto. Sunday: cook 2 lb chicken thighs (oven at 425°F, 25 min), fry 1 lb ground beef with spices, hard-boil 6 eggs, prep cauliflower rice (food processor + 10 min sauté), wash and dry greens. This gives you protein ready-to-go for 4-5 days. Weeknight keto dinners then become a 10-15 minute assembly: reheat protein + steam vegetable + dress with olive oil or butter.
Keto and exercise: what actually works
Low-intensity cardio (walking, easy cycling, yoga) works fine on keto once fat-adapted, which takes 4-6 weeks of consistent under-30g carb intake. High-intensity training (HIIT, heavy lifting, sprints) is carbohydrate-dependent and suffers during the first 4-6 weeks of keto. After adaptation, many people find their lifting performance returns to near-normal with a slight ceiling.
Targeted keto (TKD): eating 20-30g fast-digesting carbs 30-60 min before high-intensity training. This fuels the workout without significantly disrupting ketosis, as the carbs are burned during exercise. Dextrose, white rice, or banana are common choices. TKD allows strength athletes to maintain ketosis most of the day while supporting intense training.
Common keto failures and their causes
"I'm not losing weight." Keto is not a magic fat-loss protocol — calories still matter. High-fat foods are calorie-dense: 2 tbsp of peanut butter is 190 calories. Track total calories for 2 weeks to get a baseline; most people eating ad libitum on keto still hit or exceed maintenance calories.
"I'm constantly hungry." Not enough fat per meal. Fat is uniquely satiating on keto. Add half an avocado, 2 tbsp olive oil drizzled on vegetables, or a handful of macadamia nuts. If you're eating lean protein + vegetables with minimal fat, you will be hungry.
"I'm craving carbs intensely." Likely an electrolyte issue, not a willpower issue. Add sodium and magnesium. Many carb cravings on keto are sodium cravings in disguise.
"I feel terrible after 3 weeks." Most keto flu resolves in 7-10 days. Persistent fatigue past week 3 suggests inadequate calories, insufficient electrolytes, or thyroid/hormonal issues. See a doctor if symptoms persist.
Frequently asked questions
How long should I do keto? Minimum 12 weeks for meaningful fat adaptation and accurate assessment of results. Short-term keto (under 4 weeks) shows dramatic water weight loss but doesn't reflect true fat adaptation. Many people cycle keto seasonally: strict keto for 12 weeks, then maintenance low-carb (50-100g) between cycles.
Can I drink alcohol on keto? Dry wine (Pinot Grigio, Cabernet — 2-4g carbs per glass) and spirits (vodka, whiskey, gin — 0g carbs) are compatible. Beer is not (13-17g carbs per can). Sweet cocktails, liqueurs, and mixed drinks are not. Be aware that alcohol is metabolized before fat on keto — it temporarily pauses fat burning.
Is keto safe long-term? For most healthy adults, yes. Long-term studies (5+ years) on well-formulated keto diets show maintained weight loss, improved triglycerides, and stable or improved HDL cholesterol. If you have kidney disease, take insulin or diabetes medications, or have a history of eating disorders, consult a doctor before starting.
Can I have any fruit? Berries (strawberries, raspberries, blackberries, blueberries) in ½-cup portions. Avoid: bananas, grapes, mangoes, pineapple, most tropical fruit, dried fruit. One medium banana is 23g net carbs — nearly a day's budget.
Keto vs. general low-carb? "Low-carb" is any diet reducing carbs below typical intake (often 50-100g/day). Keto specifically induces ketosis by dropping below 30g net carbs. Low-carb without ketosis is easier to sustain long-term but doesn't provide the fat-adaptation and ketone-fueled cognition benefits some people report.
Related: macro meal planner, meal cost calculator, baking substitutions for keto, calories per dollar.