Several comprehensive studies and meta-analyses have demonstrated that after a few months or even a year of a low carb diet versus a moderate/high carb diet, there are no significant differences in the amount of weight lost (2,3,4,5). I will say, however, most of these diets are NOT keto and are simply lower carb (i.e. 20%). Also, long-term effects (beyond 1 year) are not often studied due to budgetary constraints, so interpret results as you wish.
Some of the concerns are around micronutrients — supplementation of electrolytes, vitamins, and fiber is often required on low-carb diets, Zeratsky says. And sometimes, these diets can actually lower the blood sugar of a person with diabetes to the point where it’s too low, which is also dangerous. (Low-carb diets are not recommended for those people with type 1 diabetes or anyone on insulin due to that risk, experts note.)
Though we singled out quinoa above, whole grains in general (we’re talking cereal, rice, pasta, and more) are conducive to weight loss, especially when they’re used in place of refined—white—grains. In fact, a study published in the American Journal of Clinical Nutrition found that substituting whole grains for refined grains in the diet increases calorie loss by reducing calories retained during digestion and speeding up metabolism. Unlike refined grains, whole grains are packed with satiating, heart-healthy fiber.
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.
Starting on a ketogenic diet can influence your exercise performance in multiple ways, both positive and negative. During the first 1-2 weeks (the “adaption period,” which I will get back to later), you will most likely see a decrease in energy and athletic performance across the board while your body adjusts to the new diet. This is perfectly normal and should NOT be a cause for concern or make you abandon the diet.
Klein S, Sheard NF, Pi-Sunyer S, Daly A, Wylie-Rosett J, Kulkarni K, Clark NG. Weight management through lifestyle modification for the prevention and management of type 2 diabetes: rationale and strategies. A statement of the American Diabetes Association, the North American Association for the Study of Obesity, and the American Society for Clinical Nutrition. Am J Clin Nutr. 2004;80:257–263. [PubMed]
You'll find lots of free Mediterranean diet resources on the Oldways website, including an easy-to-understand food pyramid; a printable grocery list; gender- and age-specific tips on making the Mediterranean switch; a quick-read "starter" brochure; a recipe newsletter; and even a glossary defining Mediterranean staples, from bruschetta to tapenade.
I have been a type 1 diabetic for most of my life. I live a very active lifestyle of long distance running and hiking. I’ve always had a very healthy diet, but would still have those after meal blood sugar spikes that would leave me feeling unwell. I decided to try the keto diet to see how my blood sugar did It’s been amazing. I’ve cut my insulin in half and my head is clear. I no longer have the brain fog. I sleep better and have more energy. I have been doing it for a year and have no desire to go off of it.
As Tammy points out, diets are diets, and many people nowadays think/feel that diets are a “time/value-based goal”. “If I just get my weight down, or if I just fix this, then I’ll be all set…” WRONG!!! There in lies the first problem. How long can it be maintained? Well that’s a good point. The real question is, how long is one committed to changing their life, and how strong is their desire to do it. ALL things that one wants to change in life, require a change in to the way their living and/or perceiving life. They require a life-style change. One could attempt a Mediterranean diet, and yet relapse back to “normal” eating after 3mos, 1yr, 3yrs, etc.. It doesn’t really matter if the change isn’t first on the mental and emotional level. Unfortunately, many first-world daily diets (namely American) incorporate many foods that are addictive which can cause cravings. And yes, the cravings are scientifically prove-able, and have been proved. We grow up thinking that it’s “normal” to have your cake (since its the carb of debate lol) and eat it too, because why?… Well because that’s how they were raised. Simply as that. Conditioned living if you will. There are many cultures on this planet that DO NOT grow up eating as many carbs and sweets as the American Diet, and do perfectly fine without all the sugars and carb cravings. And incidentally, they also lead healthier lives too… Go figure.
My principal hope in this article is to provide journalists with a resource to do what basic journalism demands, namely to ensure that stories are scientifically balanced and accurate. At the end of this post I provide contacts for some of the credentialed experts who helped me compile this research. Reporters, please seek out these or other low-carb diet experts so you can provide accurate, up-to-date information for your readers.
Body Fat Reduction. According to the current research literature, both visceral and subcutaneous fat play a role in the development of type 2 diabetes.  To keep our fat cells from fighting against us, we must adopt a healthier lifestyle that prevents us from being in a calorie surplus and gaining weight. The keto diet is one lifestyle change that has been proven time and time again to help us lose fat and improve metabolic health. 
Make this spread in advance and bring it along to work. Recipe makes two servings. Have half the recipe today, and save the rest for Wednesday's snack. Use remaining chickpeas from Monday's lunch (half a 15-ounce can). Mash the chickpeas lightly in a bowl with a fork. Mix in 2 teaspoons olive oil, 1 clove minced garlic, 1 tablespoon lemon juice and 1/4 teaspoon salt. If desired, add 1/4 teaspoon ground cumin. Mash all ingredients together thoroughly or, if a smoother spread is desired, use a food processor to blend the ingredients. Bring along 1 cup broccoli flowerets and 1 sliced red, orange or yellow pepper for dipping.
I am one of those strange people that enjoys reading about nutrition. I chose this book merely for this "diet" being listed as number one for the past few years. While I completely agree with the majority of the principals there are a few things I found disturbing. No coconut oil? However, margarine, Sugar free jello, low fat dairy products, diet drinks, and artificial sweeteners are promoted in this plan. Seriously? I am by no means a Purist but to put sugar free jello on a daily meal plan?
The crazy thing is it is not hard, if it matters. Sure I can see it being hard for someone who does it to lose weight, then when they get closer to their ideal, they want to have treats, etc. Well, for a type one diabetic there’s no end in sight, this is it, and it’s a relatively complication free life (many people reverse their complications when they bring their A1C down to normal) vs. one with inevitable complications. So, perhaps it was too hard for you after a year (you didn’t say, but I assume you are not a type one diabetic), but that is a choice you can make. Not I.
Con: Results can vary depending on how much fluid you drink. By drinking more water, you dilute the concentration of ketones in the urine and thus a lower level of ketones will be detected on the strips. The strips don’t show a precise ketone level. Finally, and most importantly, as you become increasingly keto-adapted and your body reabsorbs ketones from the urine, urine strips may become unreliable, even if you’re in ketosis.