Type 1 Keto

6. What to Eat.


 Type 1 Diabetes follows the same principles as all low carbohydrate diets: real food, healthy fats, reduced carbohydrate.

There is no science behind three meals a day. This has evolved around social habits and working patterns. Two meals a fast of 16-18 hours is often practiced by those eating low carb. It is perfectly safe in type 1 on a very low carb diet. Three meals a day plus snacks is even worse and is nothing but extreme marketing. Avoid snacks if you can. You might not be hungry at all, likely bored, sugar-addicted, stressed, or dehydrated. But it all depends on what suits you as an individual.

 The most crucial factor in managing the diet in a keto lifestyle is to cut the carbs. This is the most effective strategy for achieving satisfactory blood glucose control. Very low carb or ketogenic diets are the most effective way to do this.

There is no single dietary strategy that can be recommended for all. The body is a unique organism and might have different nutritional needs at various stages of life. We, therefore, have individual nutrient requirements. Some do well with meat, some dairy, some plants. Within each food group, there will be certain types of food that are unsuitable. An obvious example would be a vegetarian with coeliac disease. They can eat most plant-based foods except wheat. But wheat might have been perfectly okay at an earlier phase of their life. This principle operates more subtlety for a whole range of foods. Individuals will react differently to the same food ingredient. We have to factor in the metabolic changes of aging and the effects of hormonal profiles as we age.

 The majority of the population have a mixed diet, and this is the subject of this article.  The principle approach to a ketogenic diet is to work with your personal food preferences and reduce the carbs around those preferences. It might be the case that you will need to experiment around the different nutrients to get the formula right. It takes time and some degree of experimentation.

Some people will be unable to tolerate, for example, meat. This is considered by some to be the foundation of a keto lifestyle. It is possible, though, to avoid meat and dairy altogether and still manage ketosis with nutritional completeness.

The guidance below gives information on the foods that are suitable for a ketogenic diet.


All green vegetables and salads are great. Eat as much as you want. Try substituting mash, pasta, or rice for vegetables such as broccoli, courgettes, cauliflower, or green beans.  Cauliflower can be made into a rice substitute.  Pizza can be kept in the diet by substituting the carb-dense base for a cauliflower version. Courgettes can be a substitute for spaghetti if they are spiralised.

Root vegetables, in general, contain significant amounts of carbohydrate, especially potato and parsnip. Swede and carrot are less carby, but you do need to count the carbs. Celeriac is low in carb. Again, count the carbs.



Meat, preferably the fatty cheaper cuts, is excellent food on a very low carb diet. Offal such as liver, kidneys, and heart, is often overlooked but is full of nutrition and extremely cheap.  Eggs (three eggs a day is not too much), and oily fish such as salmon, mackerel or tuna, are all great sources of protein and can be eaten freely. Most protein building block molecules called amino acids are not essential. These can be made from other nutrients. But there are essential amino acids that need to form part of the diet. There are proteins in plants, including green vegetables. Other sources of protein from plants are soy, natto( fermented soy), black soybeans, lupini beans, pea protein, hemp, and chia seeds—also nuts and nut butters.  Take care to note the carbs in some nut kinds of nut butter.

The absolute minimum requirement for protein is 0.61g/kg of ideal body weight. Various organisations have added a ‘safety buffer,’ and often 0.75-1g/kg is often quoted. This is the recommended amount to consume to maintain weight and preserve muscle mass. Experts in nutritional ketosis have recommended slightly higher amounts of protein, 1-2g/kg of ideal body weight. Some people might have other reasons to eat more than this. Children and growing adults, pregnant or breastfeeding women, and those looking to gain muscle mass for whatever reason should consume more protein. Adults will need to adjust their protein intake to suit their own needs.


Healthy, naturally occurring, and unprocessed fat-containing foods are okay. Fats usually come as part of food such as cheese, nuts, and oily fish. It is often said that the fat comes along with the protein. So if you choose a protein, there will mostly be fat with it.   Fat is a source of the fat-soluble vitamins, A, D, E and K

Olive oil is especially useful. Butter is a better choice than margarine. Avoid margarine as it is a processed food with additives.  Coconut oil is excellent for frying, as is olive oil. Olives eaten whole contain 15% fat ( Olive oil). Avocado oil, linseed, and some nut butter, especially almond butter and coconut butter, are also good sources of fat.

Processed ‘vegetable oils’ are not the healthy option that was once believed.


Some tropical fruits like bananas, oranges, grapes, mangoes, or pineapples are very carby and should be avoided. Berries are better and can be eaten in small amounts. A lightly cupped handful of around ten blueberries or 2-3 strawberries is acceptable. But count the carbs. These things can soon add up over a day.  There are many other berry fruits. Apples and pears must be carb counted as some varieties are overly sweet. Fruit juices are to be avoided.


           The occasional treat of dark chocolate (85% cocoa or more) in small quantity is fine to have if the carbs are allowed for. When sugar intake is reduced or stopped, many people find their tastes change, and higher cocoa chocolate becomes the most enjoyable. Nuts such as almonds, macadamia, walnuts, pecans, hazelnuts, and brazil nuts are the less carby options. Cashews and peanuts can be higher in carbs. You will need to count the carbs as they are easy to overeat. Be mindful that snacking is causing continual stimulation of the digestive system. This might lead to glucose swings and possibly insulin resistance. Best to stick to mealtimes, if possible.


Processed meats such as bacon, ham, sausages, or salami are okay. They are not as healthy as unprocessed real meats because of the additives used in the processing. The scientific consensus on their acceptability changes almost daily, so enjoy in moderation. 


Cheese is an excellent source of healthy fat. It can make a tasty snack. Note that it is easy to consume a lot of calories when eating cheese inadvertently.



Sugar needs to be cut out completely, cakes, biscuits, cereals, and snack bars. Yes, even those ‘healthy’ ones (marketing again).

Table sugar contains 50% fructose. Fructose does not stimulate insulin secretion, but the high quantities of fructose being consumed nowadays are leading to insulin resistance and non-alcoholic fatty liver disease (NAFLD). While this is mostly associated with type 2 diabetes, it also complicates the management of Type 1 diabetes. If you have had Type 1 over a decade, then you are likely to have some insulin resistance because of the higher quantities of insulin injected to cover unnecessary carbs. If you have gained too much weight, then you are likely to be insulin resistant.

BEIGE CARBS.  It should be your goal as someone with Type 1 diabetes to aim to cut out carby foods. There are unavoidable carbs in so-called low carb foods, and adding carbs will make it challenging to reach keto levels of carbs every day. Carby foods include bread, pasta, and rice, including whole-grain versions of these foods, as they will still increase blood sugar levels to the same degree, albeit over a slightly more extended period.  There are substitutes. Rice can be made from cauliflower. Linseed can be used in a bread mix. See the recipe pages.


Sweeteners have been shown to increase hunger and may make weight loss more difficult. ‘Natural’ sweeteners such as Stevia, erythritol, and xylitol will not raise blood glucose in most cases. Artificial sweeteners such as Saccharin, Aspartame Acesulfame, and Neotame have zero calorific value but can cause insulin resistance. They are many times sweeter than table sugar and can fool the brain into preparing the bowel to digest carbohydrates even though there are none in the meal. 


Many alcoholic drinks contain significant amounts of carbohydrates. Beer contains the same amount of glucose as a slice of bread. But low carb beers are becoming available. Another choice would be the occasional spirit. Take care with mixers, which often contain a lot of sugar. Use low-calorie mixers if needed. Go for extra dry Prosecco, which is the lowest carb of any wines at 1%. A full-bodied wine could contain as much as 5% carbohydrate. The best red choice might be a Pinot Noir. The best white wine choice would be a dry Sauvignon Blanc.

Be aware that alcohol itself blocks glycogenolysis and gluconeogenesis. This means that alcohol blocks the body’s ability to raise blood glucose in a hypoglycaemic attack. Grain and grape drinks that are fermented,  such as beer and sweet wines can contain significant amounts of sugar. The combination of a glucose-raising substance such as the grain in beer, and the alcohol, can make diabetes management quite trick. 


 Cholesterol is not water-soluble, so it must be transported in the blood with lipoproteins. These include low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

LDL-cholesterol transports cholesterol from the liver out to the cells of the body, while HDL-cholesterol recycles/returns cholesterol to the liver. Traditionally LDL-cholesterol has been known as ‘bad cholesterol’ and HDL-cholesterol as ‘good cholesterol.’ (although this is by and large a crude oversimplification).

LDL-cholesterol might no longer be as important as other lipid markers such as HDL and Triglyceride.

Cholesterol is commonly misunderstood. Although it becomes problematic when coupled with inflammation, it is required for many bodily functions

The vast majority of patients who use a ketogenic diet experience an improvement of critical lipid parameters or remain stable ( HDL/TG ratio increases).  10% demonstrate an increase in total cholesterol and LDL and are regarded as hyper responders. Whether this phenotype is indeed associated with an increased risk of cardiovascular disease is not known. But  LDL particle size regularly demonstrates a beneficial pattern.


LDL particles vary in size, from ‘small-dense’ through to ‘large-fluffy.’

The number of small-dense particles appears to correlate with cardiovascular risk directly, and this may be a better measure than total LDL-cholesterol level.

Typically, we do not measure LDL particle number or size. However, small-dense LDL particle number seems to directly correlate with fasting blood triglyceride level, which could, therefore, be used as a proxy measure.

A diet high in sugar and refined carbohydrate is thought to be a driving factor for raised fasting triglyceride levels and increased small-dense LDL particle number. Dietary saturated fat has no role in the causation of heart disease and might be protective against stroke. Journal of the American College of Cardiology 17 June 2020 online review. https://www.onlinejacc.org/content/early/2020/06/16/j.jacc.2020.05.077

Considering the vital role cholesterol plays, it is important we take an educated approach to cholesterol.  It has a crucial role in cell membranes, including the brain and peripheral nerve myelin sheaths. Cholesterol is also a precursor for bile salts and steroid hormones; progestogens, glucocorticoids, mineralocorticoids, androgens, and oestrogens,

Total cholesterol is a poor marker for cardiovascular risk overall. There is no such thing as ‘serum cholesterol’ as it is not transported as a free form but as a passenger in lipoproteins or chylomicrons.

The gut absorption of fat into the lymphatic system and then the thoracic duct means that it enters the arterial circulation first and is absorbed by tissues before modification in the liver. Quality dietary fats are, therefore, essential in this respect. Cholesterol carried in LDL lipoproteins with apoB100 expressed on the surface is linked to heart disease. This is a stronger link than the association with unfractionated LDL.

The sole origin of apoB100 is the liver. A significant amount of liver fat is derived from the conversion of excess carbohydrates to fat. This will be packaged as apoB100 for dispersal to tissue receptors along with hepatic derived cholesterol. Increased cholesterol is produced through the genetic up-regulation of HMGCoA reductase (the same enzyme blocked by statins) under the influence of raised insulin levels stimulated by carbohydrates. So, it can be argued that carbohydrate intake is driving cardiovascular disease much more strongly than cholesterol, which is ‘downstream’ of the causative metabolic upset. There is an emerging consensus that carbohydrate intake in excess is leading to insulin resistance, which is the prime driver of cardiovascular disease.  Highly processed foods amplify the effects of insulin resistance and cause oxidation of the LDL particles, shifting their particle size distribution and causing them not to be cleared in the usual way. Low carbohydrate healthy fat, real food might go a long way to correcting this imbalance.


It depends entirely upon the confidence of the patient and what the patient wants to do. There are some people with Type 1 diabetes who seem to be able to achieve control and eat a low-fat, high carbohydrate diet and do not seem to get complications with slightly higher HbA1c.

These are probably happy the way they are and will not be looking to change things.

Then others are keen to start as soon as possible because they feel that their control is poor. It is up to the partnership between the clinician and patient

to work out how quickly the transition to a lowered carbohydrate or ketogenic diet should happen.

If patients manage their basal insulin levels to the optimum and are confident

in carbohydrate counting, they can achieve ketosis within 2-3 weeks.

Improved metabolic control will happen from day one if the patient decides on a more radical approach. 

Others might want to go more slowly and reduce the carbohydrate in their meal in a stepwise fashion over several weeks. Some might prefer to reduce carbohydrates in their meals just one meal at a time. It is an individual choice. Many people might not want to go to very low carb diets in the 30g a day range, but prefer to use more carbohydrates.

The aim is to achieve near normoglycemia 24 hours a day, and it is not unrealistic to expect this with a ketogenic (30g carbohydrate per day) diet. Do not encourage the patient to become obsessed with ketosis.


Inevitably by reducing dietary carbohydrate and burning fat, there will be ketogenesis, but ketosis is not the sole aim of the very low carb diet. The aim is near-normal or normoglycemia (with the least amount of insulin possible). Having to balance insulin with carbohydrates means that blood glucose levels will sometimes be suboptimal, and the patient will be briefly non-ketotic, this is unimportant as long as glycaemic control is improved.

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