Can the Keto Diet Affect a Man’s Fertility?

Keto Diet Effect on Male Fertility
Greece and food: Not sure how they did it but they nailed it! (Courtesy:

Name something you routinely do every day that has the single largest impact on your health. Sleep? Nope. Exercise? Nope. Eating? Yup.

Do you doubt the power of food? Then please consider the French Paradox: the fact that heart disease among the French is incredibly low despite an American-equivalent, fat-loaded diet. And then there’s the fact that stomach cancer rates drop and colon cancer rates rise among Asian immigrants to America. Lastly, the only known cure for diabetes is weight loss.

You really are what you eat.

The Keto Diet

The most recent diet trend is the ketogenic diet. It is a rigorously specific, low-carb, high-fat diet that is quite similar to its Atkins and low-carb relatives but is far older than either of them: It was developed in 1921 to control epilepsy in children. Essentially, keto recommends consuming 3 calories of fat for every 1 calorie of protein or carbohydrate. And that puts the body into ketosis, hence the name of the diet. But, is this newly popular diet good for male fertility?

Key Keto Concepts

The good news about the keto diet is that it’s great for controlling epilepsy and promoting weight loss. Keto followers typically lose twice as much weight as low-fat dieters. The reason it’s so good at weight loss is that the body prefers getting its energy from carbs if at all possible. When carbs are scarce, the body turns to fat for energy, burning up fat stores instead. Keto-friendly foods include fish, shellfish, meat, poultry, eggs, cheeses, Greek yogurt, olives and non-starchy vegetables such as avocado, spinach, Brussel sprouts, broccoli and cauliflower. Nuts and seeds are great as are most berries. And believe it or not, butter, cream and dark chocolate fit the bill as well. But, sugar and white flour-based foods are absolutely out.

But there may be downsides to eating keto. Bad or fruity-smelling breath, low blood pressure, low blood sugar, weakness and fatigue are common at the start. Constipation, short-term decreases in exercise performance, elevated cholesterol, kidney stones and constipation have also been described. I guess it’s true that every action brings a reaction.

Modern vs. Heritage Diets

I’ve recommended other diets before to optimize reproductive health, including Paleolithic and Mediterranean, depending on whether you look back 333 generations (Paleo) or 33 generations (Mediterranean) into human history. Keto and paleo diets are very similar in that they are both low carb-based. Keto was specifically designed to manage neurological disease and not necessarily weight loss. Paleo was designed for weight loss and focuses more on meat eating and acquiring calories from protein, much like early human cave dwellers did who had little access to grain and greens. Paleo gets its energy from animal products high in protein and low in carbs and simply eliminates all dairy, grains and processed foods, but offers no formal prescription regarding the intake of these sources of energy. Keto focuses on specific ratios of the three major energy sources: fat, carbs and protein. Paleo is cave-man-loose whereas keto is modern-man-biospecific.

The Mediterranean diet is far less of a “diet” than a philosophical “way” of eating when compared to keto. It focuses on plant-based foods, fresh fruits and vegetables, lean protein and avoidance of processed foods, but doesn’t specify how many grams of this or that to consume. The Mediterranean diet also includes exercise and sharing meals, and promotes a deeper appreciation of life. If you’ve been to Greece or Italy, you know what I’m talking about.

So which diet is best for a man’s fertility? Who knows? All three are far more antioxidant rich and healthier than the bloaty, starchy-carb, airport-food-based American diet to be sure. So, choose one and stick with it. And you’ll be a better, more fertile and longer living man because of it.