As a man in my 40s who has lost a considerable amount of weight on the keto diet, I get asked frequently about whether it is a good lifestyle choice as we begin to get older. One of the most common questions I’m asked is as follows:
I’m interested in starting a keto diet for weight loss, but I’ve heard it’s not recommended for people over the age of 40. Is this true?
For some reason, people think of a ketogenic diet as a lifestyle for younger people. The truth is, there are many benefits that ketogenic eating provides, especially for those who are over 40 years old.
In this article, I’ll discuss whether or not keto can be used successfully for people over 40 and why it may be a good option for you to follow.
What Does Ketosis Mean For Older People?
WebMD, a popular medical website, defines ketosis as what happens when you do not consume enough carbohydrates for your body to burn for energy. Instead, it turns body fat into fuel, burning it for energy.
Obviously, burning fat is a good thing, but can ketosis cause issues in older people? It can, but not for the reasons you may be thinking of. While consuming a regular diet, your body stores the carbohydrates you consume in the form of glycogen. When you enter ketosis, one of the first things your body does is deplete glycogen. Since a lot of water is stored in glycogen, it gets released in the form of urine.
That’s right. When you start keto, you will find yourself urinating more than normal. This is not an issue for most people, but if you are older and find yourself with a bladder that isn’t as strong as it once was, this can cause problems. The urge to urinate more often comes from your body trying to maintain an average pH level.

While ketosis is technically considered a metabolic process, that doesn’t mean it cannot have any side effects. Two things that people worry about when entering ketosis are kidney stones and dehydration. Dehydration is easy enough to overcome by drinking more water and including electrolytes. Kidney stones can be a little trickier. According to an article published by the University of Chicago, Jill Harris, LPN, states that kidney stones are more common among adults once they reach middle age. Again, ensuring you stay hydrated goes a long way toward keeping kidney stones from developing.
If you are worried about these potential side effects, you’ll be happy to know that they aren’t inevitable. While your risk of experiencing them does increase as you get older, they don’t happen to everyone.
You’re more likely to experience less serious side effects like tiredness, headaches, constipation, and dizziness. These symptoms are usually temporary and go away once your body adjusts to being in ketosis, so don’t let them stop you from embarking on this journey. As a matter of fact, I felt healthier once my body adjusted. I just had to get through the rough patches in the beginning.
Before we continue, if you’d like to know more about the most common side effects when starting keto, check out my article titled 12 Side Effects of Keto Diets.
Is Keto Right For Everyone Over 40?
Many doctors don’t recommend keto for those over 40, but that isn’t because it doesn’t work. For the most part, medical professionals are beginning to come around, but the evidence they are looking for isn’t quite there yet. You have to remember that most doctors won’t recommend something if there isn’t a long history of medical evidence, but that doesn’t mean keto doesn’t work.
Cholesterol and cardiovascular diseases rank near the top concerns for adults over 40. A study from Experimental and Clinical Cardiology shows keto helps decrease levels of bad cholesterol. In contrast, another study published by the Oxford Academic Journal of Nutrition reveals that people with increased ketones in the bloodstream reduce the risk of developing several cardiovascular diseases.
I also take a deep dive on how keto affects your blood pressure in Will The Keto Diet Raise Blood Pressure if you’d like to dig a little deeper.
While these benefits are enough to consider a ketogenic diet, most people turn to keto for weight loss. A lot of research is being done worldwide to determine how effective keto is at helping people lose weight. If you want to drop unwanted pounds without drastically cutting back on calories or performing hours of exercise, keto could be an ideal solution.
The Keto diet is also one of the few that seem to work for both men and women. As good as keto has worked for me and many others, it is essential to note that it is not suitable for everyone.
One group of people who must be extremely careful with their diets is diabetics. If you have diabetes and are following a ketogenic diet, you have to make sure to monitor your glucose levels closely. With that said, keto can be very beneficial for people with diabetes, as you can see in this article. As with any diet program, you want to consult with your doctor before making any drastic lifestyle changes, especially if you are on medication.
How Long Will My Body Stay In Ketosis?
It’s hard to say precisely how long your body will remain in ketosis. It depends on many factors, such as what food you consume and how active you are.
Some people get into ketosis and stay that way permanently as long as they follow a ketogenic lifestyle. Some people stay in ketosis for several weeks to a couple of months before they need to start making adjustments to their diet. Others struggle to get into ketosis and have to figure out why.
If you find yourself struggling to stay in ketosis, try not to worry too much. All you need to do is continue taking small steps until you get the hang of it. At that point, you can continue making tweaks and adjustments to fit your dietary needs.
I also find that many worry about whether it’s a good idea to keep your body in ketosis over an extended period. After getting this question many times, I wrote an article with some great information on the topic. Check out How Long Should I Keep My Body In Ketosis.
What If I’ve Tried Everything And Still Can’t Get Into Ketosis?

Starting keto can be frustrating, especially when it feels like you’re doing everything right and can’t seem to get into ketosis. I don’t recommend these long-term, but some quality keto meal replacement shakes on the market can help you get into ketosis.
I will warn you that some products from multi-level marketing companies (MLM) promote drinks that promise to help you get into ketosis instantly. I want to clarify that these products are scams and are not what I am talking about here.
The meal replacement shakes I’m describing contain a real combination of healthy fats and protein while being low in carbohydrates. In my opinion, some of the best-tasting keto meal replacement shakes on the market are made by a company called Keto Chow. These meal replacements are filling and come in a variety of flavors. Since they are keto, you mix them with water and a fat source of your choosing. Many people choose heavy cream, but I love using melted salted butter as it seems to bring out the flavors of the shake better.
If you have never tried Keto Chow, click here to try their variety starter bundle that includes 16 high-quality keto meal replacement shakes, a shaker bottle, daily mineral drops, electrolyte drops, measuring tape, and a keto quick start guide.
If meal replacements aren’t your thing, many people succeed in intermittent fasting. Fasting occurs when you set aside a short to eat each day and fast for the remaining time. When I do intermittent fasting, I find that a 16:8 schedule works best for me. This is when you fast for 16 consecutive hours and only eat during the 8-hour feeding window. During your fasting time, you consume nothing but water or black coffee.
If you find that you are overeating during your feeding window, you can shorten it. I’ve seen people do a 20:4 window, and I’ve even seen some do a 23:1 window where they only eat one large meal a day during their one-hour feeding window.
When fasting, you naturally eat smaller amounts of food, allowing your body to burn off the excess fat. But, ultimately, it all comes down to your personal preference. If you can’t decide which one may work best for you, try them both. They are excellent options for anyone who wants to lose weight and live a healthier lifestyle.
If you feel like you’re doing everything right and still can’t get into ketosis, check out my 11 Reasons The Keto Diet Might Not Be Working For You and see if anything on the list stands out to you.
Should I Eat More Protein On A Ketogenic Diet?

Protein intake is one area where individuals tend to disagree. Some people believe that keto should include very little protein, while others think you should eat higher amounts.
The Harvard T.H. Chan School of Public Health did a study on the keto diet and concluded that about 10-20% of your daily calories should come from protein. This means if you are consuming 2,000 calories a day, you should be eating approximately 75 grams of protein.
It is important to note that if you are working out, protein is vital to building lean muscle. So if you are lifting weights to build muscle instead of just burning fat, you may want to consider increasing your protein a bit.
Are There Any Foods That Are Bad For Me On Keto?
There are definitely some foods that you should avoid while following a keto diet. Sugar and carbohydrates are the most obvious and should be avoided entirely. You should also limit the amount of caffeine and alcohol you consume daily. All three of these substances can affect your ability to be successful on keto.
Alcohol is known to interfere with insulin metabolism, which is something you want to avoid on keto. Caffeine can also affect insulin metabolism, which is why many people limit themselves to one cup of coffee daily. Finally, sugar is your worst enemy on keto. It is found in many processed foods, so it is best to eliminate them from your diet completely.
On the other hand, there are some foods that you can enjoy on a keto diet. Some of the most popular include avocados, nuts, coconut oil, eggs, and butter. If you are confused about which foods are allowed, check out my list of keto foods that won’t break the bank.
Can I Drink Alcohol On A Keto Diet?

I touched on this above, but it might be better to dig in a little deeper. Many people believe that drinking alcohol while following a ketogenic diet is fine, but for most people, it really isn’t a good idea. Not only does alcohol disrupt insulin metabolism, but it also leads to dehydration. Dehydration can result in headaches, fatigue, and cramps.
This may seem extreme, but you should avoid it whenever possible. Instead, drink lots of water and ensure you get plenty of sleep. If you really must have a drink, choose a dry red wine or low-carb beer option. The wine contains antioxidants and B vitamins, while the beer is mostly water and contains fiber.
Can I Drink Coffee or Tea On A Ketogenic Diet?

You can absolutely drink coffee or tea on a ketogenic diet. In fact, drinking coffee or tea regularly is one of the easiest ways to limit your daily caloric intake. Just make sure you opt for decaf whenever possible and watch your portion sizes. Don’t pour a giant thermos of coffee. Istead, sip slowly and savor every last drop.
You will also want to ensure that you drink plenty of water while drinking coffee. If not, you may find yourself dehydrated.
Can I Have Dairy Products On A Keto Diet?
Dairy products are generally okay on a keto diet, but again, it depends on how much of it you want to consume. You should be fine if you stick to moderate portions and it fits into your macros. Be sure that you are reading labels carefully before purchasing. Some dairy products use artificial sweeteners that are not keto-approved.
Final Thoughts
As someone who has found success on keto and is 40 years old, I cannot recommend keto enough. Just be sure to do your research and make sure it is something you can stick with long-term.