The risks are more long term, such as risk of nutritional deficiency (vitamin c, a, k and b vitamins) and also increased risk of bowel and possibly breast cancer cancer due to limited fibre intake. Ketosis generally isn’t recommended and it’s not exactly a state that would the body would usually be in, but it can be done safely for set periods of time.’
U.S. News’s Best Diets rankings are put together by a panel of nutritionists, dietary consultants, and doctors specializing in diabetes, heart health, and weight loss. Each member of the panel scored all 41 diets in seven different areas, including how easy they are to follow, how well they protect against chronic disease, and how likely it is that followers will actually lose weight and keep it off.
What makes this "diet" so great is that it’s a lifestyle, not a traditional weight-loss plan that has you counting calories or measuring portions. It's all about enjoying meals with friends and loved ones, savoring each flavor, indulging in delicious, quality items like flavorful cheeses and desserts, and making time for plenty of physical activity (ah, to be walking on the beaches of Greece right now!).
WH verdict: It’s still a diet by any other name, but props to Weight Watchers for acknowledging that there’s more to being healthy than ‘weight’. The new platform really does consider all aspects of wellness. And with plans to partner with Alexa and Google Assistant to help track your progress, WW could be to 2019 what Weight Watchers was to the early noughties.
The trick here is not only to avoid all obvious sources of carbohydrate (sweets, bread, spaghetti, rice, potatoes), but also to be careful with your protein intake. If you eat large amounts of meat, eggs and the like, the excess protein will be converted into glucose in your body. Large amounts of protein can also raise your insulin levels somewhat. This compromises optimal ketosis.
Cons: Teaching your body to burn fat instead of carbs takes time, so you have to be patient while you feel sluggish during the weeks it takes to become fat-adapted. And not every body burns fat as efficiently as carbs, so your endurance may never measure up (though, as we said before, others actually see an improvement here.) Without carbs, your body’s ability to generate explosive energy will most likely decline, so if you love sprinting or HIIT, you might need to consume more carbs than other low-fat dieters. And while you’ll probably lose body fat, this kind of diet is actually keeping you focused on the wrong macro: Studies have proven that the higher protein aspect of a low-carb diet helps promote weight loss, rather than the lower carb count.
The Academy of Nutrition and Dietetics (AKA the top nutrition authority in America) released a revised paper this year saying that both vegetarian and vegan diets are best for people's health as well as the environment. If you're not ready to make a complete shift to meatless and cheese-less, consider "part-time" vegan and vegetarian plans, where you eat mostly plant-based at breakfast and lunch or on weekdays, and then eat fish, meat, dairy, and eggs only during designated times.