Every study seems to support cognitive and health benefits for IF. Studies are coming out showing it may help stave off heart disease and it’s even been shown to halt or possibly reverse brain-related diseases such as Alzheimer’s. If in doubt, check out Jason Fung’s youtube videos along with a couple of youtube researchers who do wonderful analytics, an American who lives in Japan who goes by, “Things I’ve Learned” and Thomas DeLauer’s IF material. I’ve been doing IF myself for a few months now and I feel better, more energy, better sleep, and controlled weight.
It is important to understand that weight is entirely a function of input and output. The input is the food you eat and the calories contained therein. The output is your energy output. To lose weight the output needs to be greater than the input. It is that simple. Do not believe any of the diet fads. If you are currently not gaining or losing weight then just burning 300 extra calories per week or eating/drinking 300 calories less per week (2 sodas for example or a small burger) WILL make you lose weight - in this case around 5 pounds of fat per year.
When your body burns its stores of fat, it can be hard on your kidneys. And starting a ketogenic diet -- or going back to a normal diet afterward -- can be tricky if you’re obese because of other health issues you’re likely to have, like diabetes, a heart condition, or high blood pressure. If you have any of these conditions, make diet changes slowly and only with the guidance of your doctor.

To encourage ketone production, the amount of insulin in your bloodstream must be low. The lower your insulin, the higher your ketone production. And when you have a well-controlled, sufficiently large amount of ketones in your blood, it’s basically proof that your insulin is very low – and therefore, that you’re enjoying the maximum effect of your low-carbohydrate diet. That’s what’s called optimal ketosis.


H. Guldbrand, B. Dizdar, B. Bunjaku, T. Lindström, M. Bachrach-Lindström, M. Fredrikson, C. J. Östgren, F. H. Nystrom, “In Type 2 Diabetes, Randomisation to Advice to Follow a Low-carbohydrate Diet Transiently Improves Glycaemic Control Compared with Advice to Follow a Low-fat Diet Producing a Similar Weight Loss,” Diabetologia (2012) 55: 2118. http://link.springer.com/article/10.1007/s00125-012-2567-4.
It is important to understand that weight is entirely a function of input and output. The input is the food you eat and the calories contained therein. The output is your energy output. To lose weight the output needs to be greater than the input. It is that simple. Do not believe any of the diet fads. If you are currently not gaining or losing weight then just burning 300 extra calories per week or eating/drinking 300 calories less per week (2 sodas for example or a small burger) WILL make you lose weight - in this case around 5 pounds of fat per year.
Some people feel better supplementing the already active T3 (sometimes prepared from pig thyroid glands), as it can give a stronger effect than the T4 hormone, but its effect is often harder to control. Most health professionals rarely prescribe or offer such T3 treatment, as it appears to lack significant advantages and may pose a risk when doses are high for an extended period of time. However, T3 replacement is popular among some functional medicine practitioners and naturopathic doctors. Regardless, the key is making sure you follow your levels and symptoms to make sure you aren’t over- or under-replacing thyroid hormones.
As a lifestyle-leaning research doctor, I needed to understand the science. The Obesity Code seemed the most evidence-based summary resource, and I loved it. Fung successfully combines plenty of research, his clinical experience, and sensible nutrition advice, and also addresses the socioeconomic forces conspiring to make us fat. He is very clear that we should eat more fruits and veggies, fiber, healthy protein, and fats, and avoid sugar, refined grains, processed foods, and for God’s sake, stop snacking. Check, check, check, I agree. The only part that was still questionable in my mind was the intermittent fasting part.
Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. They may recommend a different weight-loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.
Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. They may recommend a different weight-loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.
Sharon M. Nickols-Richardson, PhD, RD, , Mary Dean Coleman, PhD, RD, Joanne J. Volpe, Kathy W. Hosig, PhD, MPH, RD, “Perceived Hunger Is Lower and Weight Loss Is Greater in Overweight Premenopausal Women Consuming a Low-Carbohydrate/High-Protein vs High-Carbohydrate/Low-Fat Diet,” The Journal of Pediatrics: Vol 105, Issue 9: 1433–1437; September 2005. http://www.sciencedirect.com/science/article/pii/S000282230501151X.
#6) Zero-calorie beverages are okay. I drink green tea in the morning for my caffeine kick while writing. If you want to drink water, black coffee, or tea during your fasted period, that’s okay. Remember, don’t overthink it – keep things simple! Dr. Rhonda Patrick over at FoundMyFitness believes that a fast should stop at the first consumption of anything other than water, so experiment yourself and see how your body responds.
If you want to lose weight, consider starting by avoiding sugar and starch (like bread, pasta and potatoes). This is an old idea: for 150 years or more there have been a huge number of weight-loss diets based on eating fewer carbs. What’s new is that dozens of modern scientific studies have proven that, yes, on average low carb can be the most effective way to lose weight.
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