Keto diet foods

The numbers are grams of digestible carbs per 100 grams, i.e. net carbs ↩

This is controversial, and scientific findings are still preliminary [very weak evidence].

For a full guide to the health effects of red meat, check out our full guide.

Grass-fed meat tends to be higher in omega-3 fat, conjugated linoleic acid (CLA) and vitamins, per gram, which theoretically could be a good thing. These animals may also be raised in a more ethical way.

However, it’s unknown if improved nutritional contents of meat results in better health. From an evolutionary perspective eating grass-fed rather than grain-fed meats should more closely match the environment of our ancestors, which could potentially have some positive health effects. To date, we do not have any trials to support this claim. Putting it into perspective, the omega 6:3 ratio in conventional beef is still better than chicken, and the the total omega 3 content is still far below fish.

The available evidence only show that grass-fed meats can have a slightly different nutritional profile, which can also change the biochemical profile of the cell structures of humans eating it:

British Journal of Nutrition 2011: Red meat from animals offered a grass diet increases plasma and platelet n-3 PUFA in healthy consumers [moderate evidence for a different nutritional effect]

Nutrition Journal 2010: A review of fatty acid profiles and antioxidant content in grass-fed and grain-fed beef [moderate evidence for slightly different nutritional profile of grass-fed meat]

Regarding unprocessed red meat in general, its health effects are controversial. But it’s clear that it’s nutritious and satiating, and that humans have been eating it for millennia. We see no good health reasons to avoid it: Guide to red meat – is it healthy? ↩

There’s a lack of clear scientific evidence about what level of protein intake is most beneficial on a keto diet. Quite likely it depends on your goals.

As a general guideline, stay around 1.2-1.7 grams of protein per day, per kg of reference body weight – about 100 grams of protein per day if you weigh 70 kilos (154 pounds). See our guide on how much protein we should eat for more details.

Younger, fit people who exercise a lot may be able to tolerate quite a lot of protein and still stay in ketosis.

Too much protein inhibiting ketosis is a somewhat common anecdotal report from our members and others with diabetes. However, there appears to be a disconnect between anecdotal concerns and published research regarding its frequency.

Here are some thoughts on individualization of protein intake, and details about the views of different low-carb experts. ↩

Studies suggest that farmed fish may often have higher levels of pollutants and that they can be lower in essential omega-3 fats:

Environmental Health Perspectives 2005: Risk-based consumption advice for farmed Atlantic and wild Pacific salmon contaminated with dioxins and dioxin-like compounds[overview article; ungraded]

Public Health Reviews 2018: Food safety impacts of antimicrobial use and their residues in aquaculture[overview article; ungraded]

Science 2004: Global assessment of organic contaminants in farmed salmon [observational study; weak evidence]

Scientific Reports 2016: Impact of sustainable feeds on omega-3 long-chain fatty acid levels in farmed Atlantic salmon, 2006–2015 [non-controlled study; weak evidence]

PLOS One 2011: Chronic consumption of farmed salmon containing persistent organic pollutants causes insulin resistance and obesity in mice [mouse study; very weak evidence]
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The scientific support for this is not strong [very weak evidence].

From an evolutionary perspective eating pastured eggs might more closely match the environment of our ancestors, which could potentially have some positive health effects.

According to some studies (like the one below), organic or pastured eggs have higher nutritional contents. But studies do not consistently show a large difference, and no human outcome trials exist.

Renewable Agriculture and Food Systems 2010: Vitamins A, E and fatty acid composition of the eggs of caged hens and pastured hens [moderate evidence for different and possibly improved nutritional profiles]
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Yes, this exact number is a bit of a joke. But the reality is that for your health, it does not appear to matter much how many eggs you eat. So there’s no good reason to have an upper limit at all. Eat all the eggs you want.

Do you worry about eating saturated fats or cholesterol? There’s no good reason to do so. While still a bit controversial, repeated modern systematic reviews find no benefit from avoiding saturated fats, or replacing them with unsaturated fats:

• Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]
• Nutrition Journal 2017: The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials [strong evidence]

Here’s a study investigating if eating eggs for breakfast every day has any negative effects on cholesterol levels. They found none, but the egg-eating group reported greater satiety:

American Journal of Clinical Nutrition 2015: The effect of a high-egg diet on cardiovascular risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) study-a 3-mo randomized controlled trial [moderate evidence] ↩

Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]

More studies ↩

Technically, avocado is a fruit. But we list it as a vegetable as that is how most people think of it. ↩

There’s no good reason to fear natural saturated fats, including from dairy:

Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]

In fact, if anything, people eating higher-fat dairy products tend to on average have lower body weight and possibly fewer metabolic issues:

European Journal of Nutrition 2013: The relationship between high-fat dairy consumption and obesity, cardiovascular, and metabolic disease [weak evidence] ↩

This is based on clinical experience of low-carb practitioners and was unanimously agreed upon by our low-carb expert panel. You can learn more about our panel here [weak evidence]

However, there’s also some support from this study that found only minor increases in these side effects, while advising participants to drink salt-containing bouillon:

Nutrition & Metabolism 2008: The effect of a low-carbohydrate, ketogenic diet versus a low-glycemic index diet on glycemic control in type 2 diabetes mellitus [moderate evidence] ↩

More on this here:

Is drinking coffee with butter and oil the key to weight loss? ↩

Read labels on some herbal or specialty teas to make sure it does not contain added sugars or sweeteners. Be careful of herbal teas with licorice flavouring, as these have been known to raise blood pressure, lower potassium, or cause erratic heart beats in some people. ↩

Many local butchers and health food stores are now making bone broth for purchase. In a pinch, you may want to sip commercial beef stock or chicken stock, choosing organic brands with the most natural, and shortest, list of ingredients. However, be aware that many of these commercial brands – even when called “organic” – may be far from the real thing, containing little more than regular salt and flavoring. ↩

There’s a lack of stronger scientific support for this, and it’s mainly based on logical arguments, basic science, and the experience of individuals [very weak evidence]. Here are the main arguments:

• Alcohol is generally considered empty calories – adding pure energy
• Alcohol is usually metabolized first by the liver, slowing down fat burning somewhat
• Excess consumption of alcohol might lead to fatty liver, resulting in insulin resistance and thus increased levels of the fat-storing hormone insulin
• Some alcoholic drinks, like beer or sweet drinks, have a double negative effect on body weight due to the sugar and other rapidly absorbed carbohydrates.
• Alcohol can impair judgement and reduce impulse control, increasing the likelihood of eating unplanned and non-keto foods, that can slow weight loss.

This study supports a few of the points above:

The Journal of Clinical Investigation 1988: Ethanol causes acute inhibition of carbohydrate, fat, and protein oxidation and insulin resistance ↩

Even zero-calorie sweeteners may have some negative effects, including maintaining a preference for sweet tastes, and increased reward, potentially increasing the risk of overeating and even food addiction. This is mainly based on clinical experience [weak evidence].

There is also one RCT study showing weight loss from avoiding artificial sweeteners:

The American Journal of Clinical Nutrition 2015: Effects on weight loss in adults of replacing diet beverages with water during a hypoenergetic diet: a randomized, 24-wk clinical trial [moderate evidence] ↩

Wholegrain products are also full of carbohydrates, and thus not part of a keto diet.

Do you need whole grains for health? Probably not. The most recent Cochrane review of high-quality nutrition science found no evidence for that theory:

Cochrane reviews 2016: Whole grain cereals for cardiovascular disease [strong evidence for lack of any proven effect on heart health] ↩

Lack of health benefits:

Open Heart 2016: Evidence from randomised controlled trials does not support current dietary fat guidelines: a systematic review and meta-analysis [strong evidence]

Many people feel that margarine tastes worse, example:

Consumer Reports 2017: Spreads are dead: no one likes eating margarine anymore ↩

Overview article:

Journal of Nutrition and Metabolism 2012: Health implications of high dietary omega-6 polyunsaturated fatty acids

Fairly robust (HR>2) correlation between margarine intake and eczema or allergies:

Pediatric Allergy and Immunology 2006: Margarine and butter consumption, eczema and allergic sensitization in children. The LISA birth cohort study. [weak evidence]

Strong (HR 2.3 – 4.8) correlation between margarine intake and asthma:

Annals of Epidemiology 2005: Margarine consumption, asthma, and allergy in young adults: results of the German National Health Survey 1998. [weak evidence] ↩

This is based on consistent clinical experience of low-carb practitioners. [weak evidence] ↩

Unprocessed and minimally processed (i.e. cooking) food is what our ancestors have been eating for millions of years, and what the human animal is evolutionarily adapted to. By introducing a lot of processing, e.g. refining carbohydrates in a way that increases the speed of absorption and reduces the amount of nutrients and fiber, we change the food into something our bodies may not be adapted to, i.e. we introduce an unknown risk of side effects.

Learn more: What are you designed to eat? ↩

The idea that lower carb is more effective is mainly based on the consistent experience of experienced practitioners, and stories from people trying different levels of carb restriction [weak evidence].

There is not yet any RCT that has actually tested two low-carb diets of varying strictness head-to-head. But RCTs of strict low-carb diets appear to often show better results, compared to RCTs of more moderate or liberal low-carb diets.

RCTs of low-carb interventions for weight loss ↩

An analysis of low-carb studies showed that even when people on low-carb diets were allowed to eat as much fat as needed to feel satisfied, this did not result in a large increase in fat consumption.

Nutrition 2010: In the face of contradictory evidence: report of the Dietary Guidelines for Americans Committee [overview article; ungraded] ↩

A number of studies demonstrate that people can lose weight on low carb without being instructed to count calories, like this one:

New England Journal of Medicine 2008: Weight loss with a low-carbohydrate, mediterranean, or low-fat diet [moderate evidence]

This may be caused by a reduction of hunger:

Obesity Reviews 2014: Do ketogenic diets really suppress appetite? A systematic review and meta-analysis [strong evidence]

It may also be caused by burning more calories on low carb:

British Medical Journal 2018: Effects of a low carbohydrate diet on energy expenditure during weight loss maintenance: randomized trial [moderate evidence] Analysis ↩