How To Introduce The Keto Diet Into Your Daily Routine

How To Introduce The Keto Diet Into Your Daily Routine

Karina Reynoso

To start keto, cut carbs to roughly 20 to 50 grams a day. Build meals around healthy fats, moderate protein and non-starchy vegetables, and drink plenty of fluids. Most people need a few days to shift into ketosis. The first week can bring tiredness or headaches, so plan ahead. If you have a medical condition or take medication, talk to your doctor before you begin.

What is the keto diet?

The ketogenic, or keto, diet is a very low-carb, high-fat way of eating. When carbs are scarce, your body starts burning fat for fuel and makes ketones. This metabolic state is called ketosis.

According to the Harvard T.H. Chan School of Public Health, a typical keto diet gets 70–80% of calories from fat, 5–10% from carbs and 10–20% from protein. On a 2,000-calorie diet, that works out to about 165 grams of fat, 40 grams of carbs and 75 grams of protein.

How many carbs can you eat on keto?

Most keto plans keep total carbs under 50 grams a day. Harvard notes that some plans go as low as 20 grams. Cleveland Clinic says eating 20 to 50 grams a day usually leads to ketosis in two to four days. For some people it can take a week or longer.

Age, activity, metabolism, sleep and stress all affect how fast you get there.

How to start keto, step by step

  1. Check with your doctor first. This matters most if you take medication or have a health condition. See the safety section below.
  2. Pick a carb target. Choose a number in the 20 to 50 gram range and stick with it for a few weeks.
  3. Clear out the obvious carbs. Sugary drinks, sweets, bread, pasta and chips are the easiest places to start.
  4. Plan your meals. Write out a few go-to breakfasts, lunches and dinners.
  5. Read labels. Sauces, dressings, flavored yogurts and "low-fat" foods often hide sugar.
  6. Consider easing in. Harvard Health suggests cutting carbs gradually rather than all at once to soften early side effects.
  7. Hold off on hard workouts at first. Keep exercise light during week one, then build back up as your energy returns.

What to eat and what to limit

Foods that fit keto

Harvard's diet review lists these common keto foods:

  • Fats such as olive oil and other plant oils, butter and avocado
  • Some nuts and seeds
  • Meat, fish, eggs and tofu, in moderate amounts
  • Most non-starchy vegetables, like leafy greens, broccoli and zucchini
  • Hard cheeses, in some plans
  • Small portions of berries
  • Unsweetened coffee and tea, herbs and spices
  • Dark chocolate with 90% or more cocoa solids

Foods to limit or avoid

  • All grains and flour products, including bread, rice and pasta
  • Starchy vegetables such as potatoes, corn and winter squash
  • Beans, lentils and peanuts
  • Most fruits and all fruit juices
  • Added sugars and sweets
  • Most regular beer and wine

Keto cuts out many fiber-rich foods. Lean on vegetables to help keep meals varied and colorful.

Keto flu and electrolytes

"Keto flu" is the name people give to the rough patch some feel at the start. Harvard Health lists headache, foggy brain, fatigue, irritability, nausea, trouble sleeping and constipation. Symptoms can start two to seven days in. Energy often returns within about a week.

Part of the reason is fluid loss. A 2026 review in the Annals of Medicine explains that early on, your body passes more water. With it, you lose more sodium, potassium and magnesium. The review calls this a normal response to cutting carbs. It also notes most side effects fade within two to four weeks.

Simple ways to make the first weeks easier:

  • Drink plenty of water through the day.
  • Eat leafy greens, avocado, nuts and seeds, which supply potassium and magnesium.
  • Ask your doctor whether you should add salt or an electrolyte product. This is important if you have high blood pressure or heart or kidney problems.
  • See a doctor if you feel very unwell.

How to tell if keto is working

Cleveland Clinic lists bad breath ("keto breath") and early keto flu symptoms among common signs of ketosis. It also mentions reduced hunger. Signs vary, so they are not a reliable test on their own.

For a clearer answer, some people use a home blood ketone meter. The Annals of Medicine review defines nutritional ketosis as blood ketones above 0.5 mmol/L. That is far below the levels seen in diabetic ketoacidosis, a dangerous condition.

Also track your energy, sleep and hunger. A diet you can keep up matters more than a perfect week.

Where a BHB supplement fits in

BHB, or beta-hydroxybutyrate, is one of the ketones your body makes in ketosis. Exogenous ketone supplements provide BHB from outside the body.

A 2022 meta-analysis in Advances in Nutrition pooled 43 trials. It found that taking exogenous ketones raised blood BHB in the short term. The authors also found limited evidence on long-term use. That means it has not been shown that these supplements help with weight on their own.

If you want an optional complement to your keto eating plan, Ketosis Advanced is a BHB supplement taken as capsules twice a day. Think of it as an extra, not a replacement for keto meals. Check with your doctor before adding any supplement, especially if you take medication. You can browse more options in our weight management collection.

Who should talk to a doctor before trying keto

Keto is not right for everyone. The Annals of Medicine review advises caution or medical supervision for people with:

  • Diabetes on medication. Keto lowers blood sugar. With insulin or sulfonylureas, that can lead to low blood sugar. SGLT2 inhibitors combined with keto carry a risk of ketoacidosis.
  • Kidney disease. The review says keto is not recommended in advanced chronic kidney disease. Harvard Health also urges caution with kidney disease.
  • Liver disease or pancreatitis. Advanced liver disease and acute pancreatitis are listed as relative contraindications.
  • Pregnancy or breastfeeding. The review says keto should only be used in pregnancy with extreme care and clinical supervision.
  • Gallbladder disease or past gallbladder removal.
  • High blood pressure on medication, heart rhythm problems or electrolyte issues.
  • Being underweight.

If you have a history of an eating disorder, a strict diet with many food rules may not be a good fit. Talk with your care team before you make big changes.

Harvard also flags possible long-term concerns, including kidney stones, nutrient gaps and higher uric acid. Harvard recommends talking with a doctor and a dietitian before you start.

Frequently asked questions

How long does it take to get into ketosis?

Usually two to four days on 20 to 50 grams of carbs a day. Cleveland Clinic notes it can take a week or longer for some people.

How long does keto flu last?

For many people it eases within about a week. A 2026 review notes most early side effects resolve within two to four weeks. Water, regular meals and a slower start can help.

Can I drink coffee on keto?

Yes, unsweetened coffee and tea fit most keto plans. Skip sugar, syrups and sweetened creamers.

Do I need a supplement to do keto?

No. Keto is an eating pattern, and food does the main work. A BHB supplement can be an optional extra, but evidence for long-term benefits is limited.

Is keto safe long term?

The research is still limited. Harvard notes most studies are small and short term, and it lists possible risks like kidney stones and nutrient gaps. Work with your doctor if you plan to stay on keto for a long time.

Sources

This article is for general information and is not medical advice. Statements about dietary supplements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure or prevent any disease.

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