Keto macros in plain English: under 30g net carbs, 60-75% fat, 20-25% protein
Ketosis happens when carb intake is low enough (typically under 30g net carbs) that the liver switches to producing ketones from fat. Net carbs = total carbs minus fiber minus sugar alcohols. A 1g net-carb diet isn't required — most people enter ketosis at 20-30g. The mistake isn't carb count; it's protein. Too much protein converts to glucose and kicks you out of ketosis. Target 1g protein per pound of body weight maximum, not minimum.
The 7-day starter week: total carbs under 210g
A week of keto means 30g × 7 = 210g total carbs. Spend those carefully. Leafy greens (kale, spinach) are cheap. Broccoli and cauliflower are cheap. Berries at 5-6g per ½ cup are moderate. Nuts at 3-5g per ounce add up. Avoid all fruit juices, grains, legumes, starches, sugar-sweetened anything, and most sauces.
Fat sources: the keto protein bar
You eat fat for energy on keto. Quality matters:
- Olive oil, avocado oil: for cooking and salads.
- Butter, ghee: for sautéing and finishing.
- Coconut oil, MCT oil: for targeted ketone boost.
- Avocado, nuts, seeds: whole-food fats.
- Fatty meat (ribeye, chicken thigh, salmon): fat + protein combo.
- Cheese (full-fat): fat + protein + almost zero carb.
Avoid industrial seed oils (soybean, corn, canola) for health reasons — their omega-6 load counteracts some keto benefits.
The keto flu and how to avoid it
Days 2-5 of keto, many people get headaches, fatigue, cramps, brain fog. This is the "keto flu," caused by electrolyte loss as the body sheds stored glycogen (and with it, water and sodium). Fix: 3-5g extra sodium daily (broth, salt on food), 400mg magnesium, 1,000mg potassium. Drink water. The flu passes in 3-5 days.
Sample day: 1,700 calories, 22g net carbs
Breakfast: 2 eggs + 2 slices bacon + ½ avocado (5g net carbs, 450 cal).
Lunch: grilled chicken thigh + 2 cups spinach + olive oil vinaigrette + 1oz almonds (8g net carbs, 520 cal).
Dinner: ribeye steak + cauliflower mash + butter (6g net carbs, 650 cal).
Snack: ½ cup strawberries + 2 tbsp heavy cream (3g net carbs, 80 cal).
Weekly grocery list for 1 keto adult
Protein: 2 lb chicken thighs, 1 lb ground beef, 1 lb bacon, 1 lb salmon, 1 dozen eggs, 1 lb cheese. Vegetables: 2 lb leafy greens, 1 head broccoli, 1 head cauliflower, 1 head cabbage, 4 avocados. Fats: 1 bottle olive oil, 1 lb butter, 8 oz nuts (mixed). Extras: 1 pint berries, 1 pint heavy cream, seasonings.
Weekly cost: $80-100 for one adult, more with grass-fed/organic.
Common keto failures
"I'm not losing weight." You're probably eating too much — even keto foods have calories. Track calories for 1 week to calibrate.
"I'm constantly hungry." Not enough fat. Add an avocado or 2 tbsp olive oil to each meal.
"I crave carbs." Electrolytes. Add sodium and magnesium.
"I'm losing muscle." Too little protein. Most people need 0.7-1g per pound of lean body mass.
Keto and exercise
Low-intensity cardio works fine on keto once adapted (4-6 weeks). High-intensity training (HIIT, heavy lifting) benefits from targeted carbs — 20-30g of carbs 30 min pre-workout, within your daily limit. Long-duration endurance athletes often cycle in and out of ketosis.
Related: macro meal planner, meal cost calculator, baking substitutions for keto, calories per dollar.
Frequently asked
How long should I stay keto? 12+ weeks for meaningful fat-adaptation. Cycling in and out is fine for maintenance.
Can I drink alcohol? Dry wine and spirits only. Beer and sweet cocktails will kick you out of ketosis.
Is keto safe long-term? For most healthy adults, yes. If you have kidney disease or are on medications, check with a doctor.
Can I eat fruit? Berries only, in small amounts. ½ cup strawberries is 3g net carbs.
Keto vs. low-carb? Keto is strict low-carb (under 30g). Low-carb can be 50-100g. Keto induces ketosis; generic low-carb doesn't.