Foods and Supplements for a Ketogenic Diet

Ketosis occurs when the body is largely starved of carbohydrates but has an alternate energy source. Ketogenic products encourage the burning of fat in place of sugar/carbohydrates as a caloric source. The key is to avoid rises in blood sugar and insulin, while providing alternate fuels.

There are numerous keto-friendly products; these are considered to be those that contain fewer than 10 calories per serving of net carbohydrates (minus fiber). Fiber doesn’t raise blood sugar and insulin response, so is neutral and not counted when looking at labels. Most dietary supplements fall into the category of being ketogenic neutral; that is, they neither contain significant carbohydrate sources nor directly contribute ketogenic stimulating substances like fat. The main ketogenic products are fats: MCT and coconut oils (both contain MCTs) are the most important ones. Some take beta-hydroxybutyric acid, a ketone, directly.

Ketogenic diets tend to decrease electrolytes and increase the need for water. This increases the need for magnesium, potassium, and even sodium. If blood sugar drops too low, the kidneys can create blood sugar by converting the proteins (i.e. the amino acid glutamine) into glucose (gluconeogenesis), so high protein diets are also discouraged. This leaves non-starchy vegetables and fats as the most desirable parts of the diet, along with some protein and fiber. Nuts and seeds are often okay, but some are more starchy; check the labels. Dairy is largely out due to its lactose content, but non-dairy foods and beverages may be okay if also low carb. Fish oil supplements are desirable. Green foods are important; supplements like chlorella or spirulina can be very useful, as can wheatgrass or barley grass.

Other supplements used on a ketogenic regime include green tea and EGCg capsules, L-glutamine if exercising (it can convert to sugar, so use sparingly), 7-keto DHEA, collagen or gelatin or bone broth. Anti-inflammatory substances may also be helpful: turmeric and curcumin, ginger, etc.

Unless eating natural or fortified sources of vitamin D, or getting adequate sun exposure, supplementation of this vitamin is recommended. A multiple vitamin is the best source, assuming it has enough for your needs,  as it also supplies other nutrients needed for metabolism of fats and energy production. Calcium supplementation may be needed unless consuming lots of green vegetables. Look for digestive enzymes that supply lipase if consuming lots of fat (not needed for MCT oil). Supplements containing ox bile (also in some digestive enzyme formulas) may be needed if inadequate gall bladder function is suspected or known. Don’t forget the electrolytes!

What is the Ketogenic Diet and What Foods are Acceptable?

The ketogenic diet is a low carbohydrate (carb) diet designed to change the energy source of the brain from sugar to fats (ketones) and to increase the use of fats as an energy source in the body as a whole by severely restricting the intake of dietary carbohydrates. It overlaps a lot with the Paleo diet in that the ketogenic diet consists largely of meats and fats.

For the ketogenic diet, fish are good choices. Full-fat dairy is allowed, but fermented and unsweetened ones are preferred. Fruits are quite limited though, to small amounts of berries, plus lemons and limes in moderation, and olives and avocado (these two are fatty fruits, rather than sugary). Vegetables consist mostly of non-root ones because those have more carbs. Legumes are largely avoided, except small amounts of green beans and peas.  Nuts and seeds are used in moderation as they have some carbs; but avoid peanuts, which are legumes, not nuts. 

Fats represent most calories in the ketogenic diet: avocado oil, coconut oil, olive oil, butter, cocoa butter, MCT oil, and nut oils in moderation (i.e. walnut, sesame). Eggs and unsweetened gelatin are fine. Processed foods and condiments that have added sugars or carbohydrates should be avoided. Sugar alcohols are also avoided; stevia is acceptable, but watch for added carbohydrates in some stevia products.

Unsweetened whey protein isolate (not concentrate) has the least amount of lactose of the milk proteins; unsweetened egg white protein is also fine. Though legumes are avoided if they have carbs, unsweetened pea protein or soy protein isolates are acceptable options in the ketogenic diet.  

Excerpts from an iterview with me about natural sweeteners

A whole leaf, full spectrum extraction of stevia preserves the many phytonutrients naturally present in the plant. One study reported over 100 natural stevia phytonutrients; the majority being polyphenols and other plant antioxidants. By contrast, there are about 9 steviosides. But the new “Reb A” fraction products being sold as food sweeteners (PureVia™, Truvia™) represent only a single chemical isolated from the stevia plant, though these two sweeteners are actually sold with added sugar alcohol (Erythritol, see below) and “natural flavors”.


Some artificial sweeteners cannot be used in cooking; for example, aspartame. By contrast, natural sweeteners typically do not lose their sweetness when cooked. And studies have indicated that artificial sweeteners may backfire by shutting down the satiety signals that tell us when we’re full…in those studies the groups fed artificial sweeteners ate up to 3 times the calories as control groups.

Sugar alcohols don’t raise blood sugar as rapidly as sugar does, yet they’re as bulky as sugar so they can be used “spoon - for - spoon” to replace sugar. But their level of sweetness may vary, with xylitol being the closest to sugar. Sugar alcohols have a range of sweetness and absorption; the amount that is absorbed from the GI tract affects the possibility of it being somewhat laxative at high levels, which can vary from person to person. Sorbitol may be laxative at moderate levels of 10 grams or more, mannitol at over 20 grams; xylitol at over 30 grams. Erythritol is virtually free of a laxative side affect even at higher levels, but is expensive. Also, sugar alcohols tend to have a cooling effect in the mouth and actually taste better when combined with a different type of sweetener.

Sugar alcohols also boast an FDA-approved health claim: “Frequent between-meal consumption of foods high in sugars and starches promotes tooth decay. The sugar alcohols in [name of food] do not promote tooth decay.”

I think that organic maple syrup, agave and xylitol are doing quite well as natural sweeteners, with erythritol a more recent option that is catching up. The recent crossover of a certain isolated fraction of stevia (Reb A) as a mass market sweetener has some drawbacks: it doesn’t taste like whole leaf extract, and is combined with both erythritol and natural flavors. And there are certified organic full spectrum extractions without the typical bitter aftertaste or added flavoring agents.

Many stevia products are still only legal to sell as herbal dietary supplements, not as sweeteners. Some companies may think that all stevia products are now approved for use in foods, but that is not true. Retailers should take their cues from the packaging, and only carry reputable brands that strictly follow labeling laws. It is primarily the isolated “Reb A” fraction of stevia that can be used in foods. Most other stevias have not been approved for food use, with some exceptions.

Agave Nectar Dangers; facts and myths

The people claiming that fructose is worse than sucrose are ignorant and plain wrong. HFCS is typically 42% fructose, mostly glucose; some is 55% fructose.

Is blood sugar no longer an important issue? Diabetes statistics would seem to insist that it is still relevant. In that regard alone, fructose (with a Glycemic Index rating of 20, versus 100 for 100% sucrose white sugar) is far better than sucrose in terms of not provoking high blood sugar and the resulting insulin reactions.

And the repetition that agave nectar production is analogous to HFCS production is mind numbingly simplistic and misleading. In terms of agave production, taking inulin that's made of chains of fructose, adding non-GMO "plant enzymes" to free the fructose, then heating and filtering is not really that unnatural a process; in fact, in some ways quite similar to human digestion. HFCS production involves converting 100% sucrose corn syrup into fructose and then adding pure corn syrup to achieve the 42% or 55% fructose syrup (the rest of the 100% in each form is pure corn syrup as sucrose). There is no corn used to make agave nectar, and sugars are not converted into other forms or blended.

Studies showing that getting 25% of daily calories, around 500 calories, solely from fructose is related to obesity begs the question of why getting nearly all of our carbs from a single sugar, rather than from a mix of sugars along with fiber and starches, is anything other than a fast food worst case scenario. This is not relevant to those taking a little agave nectar in place of other sweeteners. Trying to frighten people who now won't even take a piece of whole fruit or a couple of calories worth of fructose in a chewable or liquid dietary supplement (this is actually happening!) is in my opinion both cynical and misleading. That is not honest nutrition. Common sense should be more common.

NATURAL and ALTERNATIVE SWEETENERS

Some artificial sweeteners cannot be used in cooking; for example, aspartame. By contrast, natural sweeteners typically do not lose their sweetness when cooked. And studies have indicated that artificial sweeteners may backfire by shutting down the satiety signals that tell us when we’re full…in those studies the groups fed artificial sweeteners ate up to 3 times the calories as control groups. Sugar alcohols don’t raise blood sugar as rapidly as sugar does, yet they’re as bulky as sugar so they can be used “spoon - for - spoon” to replace sugar. But their level of sweetness may vary, with xylitol being the closest to sugar. Sugar alcohols have a range of sweetness and absorption; the amount that is absorbed from the GI tract affects the possibility of it being somewhat laxative at high levels, which can vary from person to person. Sorbitol may be laxative at moderate levels of 10 grams or more, mannitol at over 20 grams; xylitol at over 30 grams. Erythritol is virtually free of a laxative side affect even at higher levels, but is expensive. Also, sugar alcohols tend to have a cooling effect in the mouth and actually taste better when combined with a different type of sweetener. Sugar alcohols also boast an FDA-approved health claim: “Frequent between-meal consumption of foods high in sugars and starches promotes tooth decay. The sugar alcohols in [name of food] do not promote tooth decay.” A whole leaf, full spectrum extraction of Stevia should preserve the many phytonutrients naturally present in the plant. One study reported over 100 natural Stevia phytonutrients; the majority being polyphenols and other plant antioxidants. By contrast, there are about 9 steviosides. And the new Reb A fraction products being sold as food sweeteners are only a single chemical isolated from the stevia plant. There is a bitter aftertaste associated with traditional Stevia products. Some mix Stevia with sugar alcohols like erythritol in order for the sweetener to mask the bitter aftertaste. The recent crossover of a certain isolated fraction of Stevia (Reb A) as a mass market sweetener has some drawbacks: it doesn’t taste like either whole leaf or other traditional Stevia extracts, and is combined with both erythritol and natural flavors. Many stevia products are still only legal to sell as herbal dietary supplements, not as sweeteners. Some companies may think that all stevia products are now approved for use in foods, but that is not true. Retailers should take their cues from the packaging, and only carry reputable brands that strictly follow labeling laws. It is primarily the isolated “Reb A” fraction of stevia that can be used in foods. Most other stevias have not been approved for food use. There is a wide selection of natural/alternative sweeteners: Organic Agave Nectar, Barley Malt powder, Organic Brown Rice Syrup (some have no gluten [usually barley malt] added; some do), Beet Sugar (for those with cane allergies), Date Sugar (look for pure dried date pieces with no oat flour added), Dextrose, Fructose, Lactose, Organic Maple Syrup, Organic Sucanat®, and Organic Turbinado Sugar.