-Cardiovascular Disease: High blood sugar has been shown to increase the risk for cardiovascular events, cardiovascular disease, and cardiovascular mortality—while lower glucose levels result in lower cardiovascular risk. Coronary artery disease risk has been shown to be twice as high in patients with impaired glucose tolerance, compared with patients with more normal glucose tolerance. The risk for stroke increases as fasting glucose levels rise above 83 mg/dL. In fact, every 18 mg/dL increase beyond 83 results in a 27 percent greater risk of dying from stroke. Incidentally, glucose can “stick” to cholesterol particles and render these particles extremely dangerous from a heart health standpoint, which is why it’s all the more important to control blood sugar levels if you’re eating a “high-fat diet.”
Protein will induce an insulin response in the body, if consumed in high amounts. The most intuitive way to start a keto diet for most people is by removing all of the carbs they have been eating. Typically people will replace those calories by increasing their lean meat consumption. That's a recipe for disaster! Keeping protein moderate is an often overlooked, but very important part of a keto diet. Most people need around 0.6g to 1.0g of protein per pound of lean body mass.
I have been taking Ucan 30 Minutes before run and take UCAN 1 Hour into run and 1 hour later. Also take BCAA powder in 8 ounce liquid during run. I have been doing HFAT and LCARB diet. Problem i slow down after 1 1/2 hour during my long run. I need your advice help fueling my run after 14 miles. This my first Marathon, I have run 7 Half Marathon around 1.58.
If you prefer a more direct, customized approach, I'd be happy to help you via a personal one-on-one consult. Just go to https://bengreenfieldfitness.com/coaching. and then choose a 20 or 60-minute consult, whichever you'd prefer. I can schedule ASAP after you get that. Additionally, if I'm "out of your price range" (yes, yes, I know I can be a spendy guy to access) I have a team of coaches I've personally trained who can help you here: https://greenfieldfitnesssystems.com/product-cate…
For anyone, regardless of any underlying health issues, the so-called keto flu is a possibility (and even likelihood) as your body adjusts to ketosis on the keto diet, says Tori Schmitt, RDN, founder of YES! Nutrition, LLC based in Dayton, Ohio. Fatigue, irritability, headaches, and nausea are all symptoms of the keto flu, Schmitt says. Fortunately, keto flu lasts only about one to two weeks.
Next, you should know that supplementing with KETO//OS (or following a ketogenic diet) can cause a slightly diuretic, water-losing effect, and can deplete your natural magnesium, potassium and sodium stores. This can be rectified by supplementing with a good electrolyte or increasing the sodium in your diet. This is another reason KETO//OS adds additional sodium to the formulation to counteract this sodium depletion.
Under these circumstances, as soon as the body’s limited reserves of glucose starts to run out, your entire body switches its fuel supply to run almost completely on fat. The levels of the fat-storing hormone insulin levels become very low, and fat burning increases dramatically. You thus get easy access your fat stores, and can burn them off. This is great for losing excess weight. Studies prove that keto diets result in more weight loss, faster. There are also more potential benefits.
Great article! As someone who just started a “ketogenic diet” two weeks ago, I am opting to hold off on using ketone supplements for the following reason. You state how “Keto-adaptation occurs when you have shifted your metabolism to relying on fat-based sources, instead of glucose (sugar) sources, as your primary source of fuel.” If the goal is to “switch” our body’s energy supply to ketones and one uses supplemental ketones, how do they really ever know if their body has successfully accomplished this goal if they are using supplemental ketones? Aren’t they getting a false sense of ketosis if their blood or breath tests show them above 0.5 millimolar through the use of the supplements? I understand that it may take me longer to reach ketosis naturally but I guess I see it was worth it to truly reap all of the benefits that you outline in your article.
3) Cholesterol levels usually go up with inflammation, because inflammation causes damage to the tissues, and cholesterol is manufactured and released in circulation to patch things up. So, again, eating high fat is the best way to drop inflammation; not increase it. My hsCRP are always below 0.1, and most of the time, below detection level. Oxidation of cholesterol causes inflammation; not the other way around. So, your point about inflammation is a non-issue.
Carbohydrates are necessary for the conversion of inactive thyroid hormone to active thyroid hormone, and if you’re on an extremely strict low carbohydrate diet, then you may actually be limiting this conversion. Your TSH is what tells your thyroid gland to “release more hormone,” so your TSH rises when your thyroid gland is underactive, or conversion of inactive to active thyroid hormone is inadequate. A high TSH means that the pituitary gland is releasing its hormone to try to get the thyroid to respond and produce more thyroid hormone. Because of inadequate carbohydrates, TSH will often elevate in a high-fat, low-carber – indicating potential for long-term thyroid and metabolic damage.

Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate,[18] leading to more food choices and larger portion sizes.[4] The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil.[15] Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant.[9] The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.[18] 

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Hi Gigi, Low carb and keto is about the balance of macronutrients eaten (fat, protein and carbs), not specifically meat or lack thereof. Most people on keto do eat meat, though some people do vegetarian keto. Fat is actually necessary for many body processes. There is no issue for the kidneys with a high fat diet, but if you eat too much protein that isn’t great for the kidneys. It’s a common misconception that keto is high protein (it isn’t). Keto is great for diabetics as it naturally helps stabilize insulin. All of this being said, please know I’m not a doctor and you should consult your doctor on any medical questions or before starting any diet. If you have more questions that aren’t medical questions, I recommend our low carb & keto support group here.
Ketones are also a cleaner-burning fuel than carbs. They’re burned for energy in the mitochondria, and fewer free radicals (a highly-reactive, short-lived uncharged molecule) are generated when compared to burning glucose.15 What’s more, ketone molecules themselves cause a decrease in production of free radicals,21,22 while also increasing glutathione–a powerful antioxidant protecting against mitochondrial damage induced by free radicals.23
Take coconut oil for example. The coconut oil industry loves to market the idea that relatively inexpensive and abundant coconut oil is a great source of MCTs because it’s “62% MCT oil”, but the problem is that studies show you can’t get many useful ketogenic MCT’s from just eating coconut oil or even most brands of “MCT oil”, which are often is diluted with lauric acid, a cheap, hugely abundant part of coconut oil that is typically marketed as an MCT oil.
Hey Alex, thanks for commenting and great to have you as a new listener! For this kind of thing, because it requires so going into detail, I'd suggest you book a consult with me by going to
Me, I was a lot of things before I was keto: vegan, high starch, skinny, an Adderall abuser, paleo, Catholic, raw till 4, pescatarian, etc. The reason I went high fat/low carb was because some very smart-sounding people on the internet told me that I could “hack my body” and eat some fun things (bacon) if only I’d cut out a food group that was probably giving me constipation and cancer anyway.
Can’t get enough of avocados? You now have a great excuse to eat more of them. A ½-cup serving of the creamy fruit has almost 12 g of fat and only 2.6 g of net carbs. Avocados are also low in calories (about 138 for the same serving), making them an ideal snack in between meals. One serving also has about 6.4 g of dietary fiber (25.6 percent daily value, or DV), 404 milligrams (mg) of potassium (8.6 percent DV), and only 2.8 g of sugar. Try topping your salad with cubed avocado for a keto-friendly lunch.
I’m missing one key-step in this whole process … I understand (vaguely) how to get into ketosis via diet, starvation, or supplementation. But, my confusion really is with the supplementation method (such as XCT Oil, for example). If I supplement with these to get into ketosis quicker, but haven’t significantly altered to a high-fat diet, won’t I just shift back into glucose-use as soon as I burn out the supplemented ketones?? like within minutes / hours?

Nutritional ketosis is a natural metabolic state in which your body adapts to burning fat rather than carbohydrates as its primary fuel. It is clinically proven to directly reduce blood sugar (as measured by HbA1c), improve insulin sensitivity (as measured by HOMA-IR) and reduce inflammation (as measured by white blood cell count and CRP). Nutritional ketosis can be induced by following a ketogenic diet. Learn more in our FAQ below!
Eat fewer calories by lowering your fat intake. On keto, protein and carb intake is usually the same for everyone, but you may want to adjust your fat intake to eat fewer calories than you're eating now. Because keto has a metabolic advantage over other weight-loss diets, you may only need to reduce your calories slightly (around 300 kcal less a day).
Those issues can be part of what's known as the “keto flu,” Warren says. Other side effects of the keto diet, all of which are tied to carb withdrawal, can include lightheadedness, nausea, mental fog, cramps, and headaches, in addition to tiredness. Luckily, the keto flu doesn't usually last more than a week—which is coincidentally about when people start to see the number on the scale go down, says Warren.
There are many misconceptions about ketosis. The most common is mixing it up with ketoacidosis – a rare and dangerous medical condition that mostly happen to people with type 1 diabetes if they don’t take insulin. Even some health care professionals tend to mix up these two situations somewhat, perhaps due to the similar names and a lack of knowledge about the distinct differences.
If you are already in ketosis and accustomed to high-fat, low-carb diets, you can take one heaping scoop in about eight ounces of water fifteen minutes prior to working out. It stays in your system and will provide your body with elevated ketone levels for about three hours. When taken as a pre-workout, KetoCaNa has also been shown to decrease the amount of oxygen consumed at a given power output.
Hi Ben, great article. I have been a keto-adapted athlete for over 2 years, all through nutrition (65/25/10). I have recently discovered UCAN, KetoOS and MAP Aminos. So, here’s my question: If I am going out for a 4-hour ride, and I want to fuel myself just on these supplements and my body’s natural fat stores, how and in what order should I take them? If I take them all together, will the aminos in the KetoOS interfere with MAP Aminos? Or should I just make a mix of the UCAN and KetoOS in 10oz of water and use it to wash back my 6 MAP tablets, 15-mins before my ride? Thanks for your advice! 

While it is believed that carbohydrate intake after exercise is the most effective way of replacing depleted glycogen stores,[72][73] studies have shown that, after a period of 2–4 weeks of adaptation, physical endurance (as opposed to physical intensity) is unaffected by ketosis, as long as the diet contains high amounts of fat, relative to carbohydrates.[74] Some clinicians refer to this period of keto-adaptation as the "Schwatka imperative" after Frederick Schwatka, the explorer who first identified the transition period from glucose-adaptation to keto-adaptation.[75]
There are so many tricks, shortcuts, and gimmicks out there on achieving optimal ketosis – I’d suggest you don’t bother with any of that. Optimal ketosis can be accomplished through dietary nutrition alone (aka just eating food). You shouldn’t need a magic pill to do it. Just stay strict, remain vigilant, and be focused on recording what you eat (to make sure your carb and protein intake are correct).

A small Feb. 20, 2017, study looked at the impact of a six-week ketogenic diet on physical fitness and body composition in 42 healthy adults. The study, published in the journal Nutrition & Metabolism, found a mildly negative impact on physical performance in terms of endurance capacity, peak power and faster exhaustion. Overall, researchers concluded, “Our findings lead us to assume that a [ketogenic diet] does not impact physical fitness in a clinically relevant manner that would impair activities of daily living and aerobic training.” The “significant” weight loss of about 4.4 pounds, on average, did not affect muscle mass or function.
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But people who started following the keto diet noticed weight loss for a few reasons: When you eat carbs, your body retains fluid in order to store carbs for energy (you know, in case it needs it). But when you’re not having much in the carb department, you lose this water weight, says Warren. Also, it's easy to go overboard on carbohydrates—but if you're loading up on fat, it may help curb cravings since it keeps you satisfied.
The ketogenic diet has been studied in at least 14 rodent animal models of seizures. It is protective in many of these models and has a different protection profile than any known anticonvulsant. Conversely, fenofibrate, not used clinically as an antiepileptic, exhibits experimental anticonvulsant properties in adult rats comparable to the ketogenic diet.[58] This, together with studies showing its efficacy in patients who have failed to achieve seizure control on half a dozen drugs, suggests a unique mechanism of action.[56]
If you’ve decided keto is a good fit for your wellness goals, and you want to add fruit to your meal plan, choose fruits with the least amount of net carbs, which is the total amount of carbohydrate content in a fruit minus its fiber content (since the body can’t digest fiber), according to the website for the popular low-carb diet Atkins. The keto diet allows for about 25 g of net carbs per day, per the healthy-lifestyle website Ruled.me. Dietitians recommend reaching for the following.
Protein will induce an insulin response in the body, if consumed in high amounts. The most intuitive way to start a keto diet for most people is by removing all of the carbs they have been eating. Typically people will replace those calories by increasing their lean meat consumption. That's a recipe for disaster! Keeping protein moderate is an often overlooked, but very important part of a keto diet. Most people need around 0.6g to 1.0g of protein per pound of lean body mass.