Dr. Gardner and his colleagues designed the study to compare how overweight and obese people would fare on low-carbohydrate and low-fat diets. But they also wanted to test the hypothesis — suggested by previous studies — that some people are predisposed to do better on one diet over the other depending on their genetics and their ability to metabolize carbs and fat. A growing number of services have capitalized on this idea by offering people personalized nutrition advice tailored to their genotypes.
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.
Blumenthal was impressed that improving diet and exercise was helpful even in this group that was at risk of developing cognitive problems and potentially even dementia. “This is not necessarily a cure, but there is currently no pharmaceutical intervention for preventing dementia,” he says. “So a starting point of improving lifestyle with exercise and perhaps diet in this group of people can have important implications down the road for their overall wellbeing.”
To minimize the importance of exercise in the equation is to completely ignore the fact that working out has the capacity to strengthen your heart and your immune system, increase bone density, ward diabetes, cancer and heart disease, increase your lung capacity, and more. For this reason, we think it's irresponsible to downplay the role of exercise in both weight loss and health.
The fact that the group following both the exercise and diet programs showed the greatest benefit suggests that the two interventions may work together to improve brain health, Blumenthal says. “We saw evidence that exercise and the diet together are better than nothing,” he says. “We showed you can get improvements in function that can reduce and certainly improve neurocognitive function, and possibly even postpone development of dementia late in life.”
You’re transitioning. Your body is equipped to process a high intake of carbs and a lower intake of fat. Your body needs to create enzymes to be able to do this. In the transitional period, the brain may run low on energy which can lead to grogginess, nausea, and headaches. If you’re having a large problem with this, you can choose to reduce carb intake gradually.
"The keto diet is primarily used to help reduce the frequency of epileptic seizures in children. While it also has been tried for weight loss, only short-term results have been studied, and the results have been mixed. We don't know if it works in the long term, nor whether it's safe," warns registered dietitian Kathy McManus, director of the Department of Nutrition at Harvard-affiliated Brigham and Women's Hospital.
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.)
Plus, Turoff gives Hadid a thumbs-up for opting for a treat she’s really into. “If you have a craving, don’t just have a handful of dry cookies — go out and get the best cookie you can find,” says Turoff. “I want people to have a healthy relationship with dessert and feel good about eating something they find delicious rather than feeling obligated to buy diet desserts.”
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.
It seems like an easy diet win: Skip breakfast and you'll lose weight. Yet many studies show the opposite can be true. Not eating breakfast can make you hungry later, leading to too much nibbling and binge eating at lunch and dinner. To lose weight -- and keep it off -- always make time for a healthy morning meal, like high-fiber cereal, low-fat milk, and fruit.