A systematic review in 2018 looked at 16 studies on the ketogenic diet in adults. It concluded that the treatment was becoming more popular for that group of patients, that the efficacy in adults was similar to children, the side effects relatively mild. However, many patients gave up with the diet, for various reasons, and the quality of evidence inferior to studies on children. Health issues include high levels of low-density lipoprotein, high total cholesterol, and weight loss.
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."
One short study among people eating shitake mushrooms daily for four weeks found that they helped lower body-wide inflammation and boosted immune functioning. Other species are being studied for their potential to fight cancer, high cholesterol, diabetes and obesity. In addition to salads, omelets, and stir-fries, consider blending mushrooms with ground beef or turkey to cut back on meat and add more plant-based goodness. Or maybe you’d like to nosh on mushroom jerky, a cool new snack that hit the shelves this year.
The fat-soluble vitamins are A, D, E, and K. Adequate absorption of these vitamins is dependent on efficient fat intake and absorption. Except for vitamin K, fat-soluble vitamins are not easily excreted from the body, so they can be toxic at excessive levels. The only way to reach toxic levels would be through taking supplements, not through your diet. This is another case when balance is the key, and excessive amounts can cause harm.
Just this week, a 25,000-person study presented at the European Society of Cardiology Congress in Munich suggested that people on the lowest-carb diets had the highest risk of dying from cancer, cardiovascular conditions, and all other causes. Another study, published this month in the Lancet, also found that people who followed diets that were low in carbs and high in animal proteins had a higher risk of early death compared to those who consumed carbs in moderation. (The opposite was true, however, for low-carb dieters who opted for plant-based proteins over meat and dairy.)
Excess body fat promotes insulin resistance, a condition in which the body produces insulin but doesn’t use it effectively—leading the body to produce even more insulin. A hormone that helps control blood sugar, insulin is a potent stimulator of prostate cancer growth. By cutting calories and increasing exercise, you may be able to reduce excess body fat, preventing or overcoming insulin resistance and limiting the amount of insulin your body produces. Also, exercising and building muscle mass help control blood sugar, lowering your need for and production of insulin.
What about fruits and vegetables? All fruits are rich in carbs, but you can have certain fruits (usually berries) in small portions. Vegetables (also rich in carbs) are restricted to leafy greens (such as kale, Swiss chard, spinach), cauliflower, broccoli, Brussels sprouts, asparagus, bell peppers, onions, garlic, mushrooms, cucumber, celery, and summer squashes. A cup of chopped broccoli has about six carbs.
Take action: Aerobic exercise has always been regarded as critical to improving brain health, but strength training is also key. In fact, the two modes of exercise benefit the brain differently, which is why it’s best to do both. In a 2013 study published in the Journal of Aging Research, the authors found that both cardio exercise and strength training improved spatial memory (for example, remembering where objects were placed in a room) in women ages 70 to 80. Cardio alone improved verbal memory (for example, being able to remember a list of words after a distraction). And in a 2012 study from the Archives of Internal Medicine, women in their 70s who strength-trained improved their associative memory, meaning that they remembered pairs of pictures that they had been shown earlier. This is the kind of memory that allows you to remember two pieces of information at once, like picturing not just your keys but also where you placed them.
A short-lived increase in seizure frequency may occur during illness or if ketone levels fluctuate. The diet may be modified if seizure frequency remains high, or the child is losing weight. Loss of seizure-control may come from unexpected sources. Even "sugar-free" food can contain carbohydrates such as maltodextrin, sorbitol, starch, and fructose. The sorbitol content of suntan lotion and other skincare products may be high enough for some to be absorbed through the skin and thus negate ketosis.
Anticonvulsants suppress epileptic seizures, but they neither cure nor prevent the development of seizure susceptibility. The development of epilepsy (epileptogenesis) is a process that is poorly understood. A few anticonvulsants (valproate, levetiracetam and benzodiazepines) have shown antiepileptogenic properties in animal models of epileptogenesis. However, no anticonvulsant has ever achieved this in a clinical trial in humans. The ketogenic diet has been found to have antiepileptogenic properties in rats.
Before you hit the road, make sure you're packing these key staples: a watch to log your total time (or a fancy GPS to track your mileage), an iPod with great amp-you-up music, a cell phone if you don't mind holding onto it, and a RoadID (a bracelet that includes all your vital info, $20; roadid.com). And on a sunny day, wear sunglasses. "They reduce glare, which can decrease squinting, ultimately releasing the tension in your shoulders," says Andrew Kastor. And that's a performance bonus, because relaxing them helps conserve energy on your runs. Hey, we'll take a boost where we can get it!
If the diet is a quick fix rather than one that promotes lasting lifestyle changes, this could pose a problem. In particular, extreme diets that promise big weight loss up front aren’t always sustainable — and you may end up overeating or even binge eating if you feel deprived. “Consider if the diet’s habits are ones you can continue throughout your lifetime, not just 21 or 30 days,” says Angie Asche, RD, a sports dietitian in Lincoln, Nebraska.