by Sue Kira, Naturopath & Nutritionist
The concept of the food combining diet is that certain foods don’t digest well together.
Some people have what we might term a ‘cast iron stomach’ and seem to be able to digest anything and everything, but there are many more people that simply cannot do this or they suffer the consequences. For example, mixing the macronutrients of fats, proteins and carbs together can create a disastrous situation for some people.
If the food you eat is not digesting properly, not only can you get painful gas, heart burn, acid reflux and other stomach problems, but your body will also be deprived of the nutrients it needs.
You put food or liquid into your mouth, chew it up, swallow it and then different processes in your body break these food particles down into a size that the body can absorb. Then anything that your body doesn’t use is excreted as waste.
Food can be broken down in different parts of your digestive system, including your mouth, stomach and the first and middle sections of your small intestine, called the duodenum and jejunum respectively. Furthermore, you have three kinds of digestion:
- Mechanical (chewing and churning) digestion
- Chemical (acids and enzymes) digestion
- Bacteria (hopefully good ones) that break down food
Food combining takes into consideration the digestive areas of your body and the complexity of digestion for each type of food, to ensure it goes through your entire digestive system with ease.
There are three primary categories of food under the banner of macro-molecules which consist of proteins, fats and carbohydrates. (Incidentally micro-molecules include vitamins and minerals)
Proteins such as meat, chicken and fish are acidic and begin their digestion chemically in your stomach, where acid (hydrochloric acid) and an enzyme (pepsin) do their job of breaking down proteins. Pepsin is a protease enzyme (protein digesting enzyme) that not only breaks down protein but also signals the release of hydrochloric acid. Hydrochloric acid as its name implies is an acid with a pH of around 3.5 For more information on pH you can read more about it at the Alkaline Diet.
With fats like oils and animal fats, digestion usually starts in the small intestine and is done with the aid of lipases (fat digesting enzymes) and bile acids (secreted from the gall bladder and liver). These enzymes and acids allow the fats to be properly broken down into individual fatty acids in the small intestine.
Carbohydrates are divided into two categories: simple carbohydrates like sugar and fruit and the second group are what are called complex carbohydrates and include starches, like grains, such as in bread and starchy vegetables like sweet potato and corn.
While carbs like fruits can pass through your digestive system quickly and easily, starches require three levels of digestive breakdown which is a much slower process.
The first stage occurs in your mouth with the action of chewing which stimulates the secretion of amylase in your mouth that mixes with the starch to break down the complex molecules into smaller ones, hence the importance of chewing your food well, especially if they are starchy foods. (Whew, that was a mouthful).
After the mouth, starch passes through the stomach to the small intestine where the pancreas secretes a pancreatic amylase (starch digesting enzyme) into the small intestine to further breakdown the starch into smaller molecules. The enzymes that break down starchy foods are alkaline, whereas proteins are broken down by acids in the stomach.
If you put an acid and an alkaline together they will neutralise each other and neither will digest efficiently. What happens next is fermentation, instead of digestion, which creates the gasses we call flatulence and bloating. Note: You can also get bloating for other reasons, such as a bacterial overgrowth in the small intestine called SIBO. More on this later.
Ideally you want to separate foods that digest differently. Acids with acids and alkaline with alkaline (although there are some complexities involved).
Eat fruit on its own on an empty stomach
If you already have digestive upsets like bloating, gas or flatulence, it is best to avoid most fruits, as they are high in natural sugars, until your symptoms have settled and your gut has had time to heal. Otherwise you may encourage the growth of any candida yeasts, parasites, bacteria and fungi in your digestive system. Your health practitioner can explain how long this process may take, depending on your individual health situation.
However, there are exceptions where sour fruits like lemons and limes or unsweetened juices from cranberries, black currants and pomegranates, can combine well with proteins and low starch vegetables such as salads.
Low sugar fruits can combine well with fermented or sprouted ‘protein fats’. Protein fats are proteins and fats that are combined by nature in the form of nuts and seeds. Mylks, yoghurts and kefir can be made from sprouted or fermented seeds and nuts (including coconut) and mixed with the low sugar fruits. For example, a blueberry coconut kefir smoothie.
The next group of low sugar fruits to enjoy after your digestive system feels better are the low sugar fruits such as grapefruit, kiwi fruit, pineapple, papaya, blueberries, raspberries and strawberries. Although pineapple and papaya seem to be quite sweet, they have a high enzyme to sugar ratio and digest quite well and can help to break down other residual food left in the stomach.
Having said that, if any of these fruits make you feel bloated or gassy, then leave them out of your diet for a longer time until you have checked with your practitioner to see if you have any dysbiosis (unfriendly bacteria imbalance).
Melon type fruits should be eaten totally alone and not even with other fruits due to their high sugar content, otherwise you risk an upset tummy.
What about vegetables that are fruits?
Generally, fruits should not be eaten with any other foods, apart from the exceptions mentioned above. But another exception are those vegetables that are, in truth, actually fruits. Any vegetable that has a seed in it is, by definition, a fruit. Examples of these are tomatoes, squash, zucchini (courgettes), eggplant, cucumber, bell peppers (capsicum) and okra.
It’s fine to eat ‘fruit-vegetables’ with other vegetables, starches and proteins as they don’t have the sugar content that most fruits have, so they are considered to be an acidic fruit-vegetable.
Eat animal proteins with non-starchy vegetables
When you eat proteins like meat, poultry, fish and eggs, your stomach creates a highly acidic environment to break down the protein, whereas starches like potatoes or rice, have to be broken down by an alkaline environment. Eating proteins and starches together will neutralize each other and inhibit digestion.
The poorly-digested food travels through the digestive tract, reaching the intestines, where it putrefies and ferments, causing acidity which creates an environment for disease-causing bacteria, fungi and yeast and potentially disease.
To prevent this from happening, avoid combining meats with grains like rice or starchy vegetables, such as corn, potatoes and sweet potatoes in the same meal. Instead, have non-starchy vegetables with your protein for optimal digestion.
Non-starchy vegetables include: leafy greens, broccoli, sprouts, cabbage, asparagus, cauliflower, carrots, red radish, bok choy, celery, lettuce, green beans, garlic, beetroot/beets, fennel, onions, chives, turnips, yellow squash, zucchini, cucumbers and sea vegetables like kelp.
Non-starchy vegetables digest quite well in both an acid or an alkaline environment, so they combined well with anything: proteins, oils and animal fats, grains, starchy vegetables, lemons and limes, and soaked and sprouted nuts and seeds.
Examples of good recipes combining proteins and non-starchy vegetable dishes are: beef and stir fry vegetables, fish with salad (not chips), roasted chicken with leafy greens (not roasted potato, sweet potato or pumpkin), or chicken and vegetable soup made with non-starchy vegetables but no grains and legumes. Dressings of simple herbs and spices mixed with olive oil and/or lemon or lime juice work well together.
Combine grains, seeds and starchy vegetables with non-starchy vegetables
Seeds, grains and starchy vegetables all contain a level of starch. The idea is to combine the right amounts of starchy foods with non-starchy foods.
Generally speaking, grains, legumes, pulses and starchy vegetables contain the most starch and are hardest to digest; seeds have less starch and are easier to digest; while non-starchy vegetables contain very little starch and are the easiest to digest.
However, there are benefits to eating starchier foods, because they contain a particular type of fibrous starch, known as ‘resistant starch’ which feed our friendly bacteria. The friendly bacteria break down the resistant starch, which our bodies cannot do.
During the breakdown of resistant starches, friendly bacteria produce metabolic substances called short chain fatty acids, such as butyrates, which have been shown to help prevent colon cancer. If our levels of friendly bacteria are low, starches will ferment in our bodies, which can lead to various health problems, including colon cancer.
Here’s a weird analogy. Think of our intestines as a steam train that’s fuelled by both wood (the starchy foods) and coal (the non-starchy foods). Too little fuel overall and the train is underpowered (low energy); too much fuel shoved in clogs up the furnace and the fire goes out. Then the train stops. The ratio (balance) of wood to coal must also be right to keep the train running smoothly and efficiently.
Likewise, your body slows down (fatigue) if it’s not fed sufficient fuel (nutrients); too much food (particularly starch) clogs your intestines, then your digestive system can’t cope and the good bacteria gets suffocated, resulting in fermentation, bloating and gas (aka excessive farting).
And if the ratio of starchy to non starchy foods is not right, further load is placed on our furnace (the digestive system) resulting in various health conditions, illness and disease.
We don’t want that, do we? So the idea is to combine a small quantity of starchy foods with non-starchy foods to provide the best balance for your digestive system.
Examples of starchy vegetables include butternut squash, pumpkin, sweet potato, corn, peas, water chestnuts and artichokes, which mix well with spinach, Bok Choy and other Asian greens.
The best seeds that are the easiest to digest are amaranth, quinoa and buckwheat. They contain protein and starch, are rich in B vitamins and help to feed the beneficial bacteria in your digestive system.
Again, here we see how nature has put two substances together i.e. protein and starch (previously we looked at a protein and fat working together in nuts). But the amount of protein in seeds is considerably lower than the protein found in animal products and so these proteins can digest quite well in an alkaline environment.
Seeds are best combined with non-starchy vegetables, however because they have a low starch content, they can still be combined with starchy vegetables in moderation e.g. pumpkin stuffed with quinoa.
Grains, legumes and pulses
Grains such as wheat, rye and barley along with starchy legumes and pulses such as chickpeas and lentils are quite difficult to digest because of their high starch content and are not the best options for those with sensitive digestive systems, or if you suffer from bloating and wind.
If you do eat these grains, legumes or pulses, then it is best to combine them with non-starchy vegetables and not with protein foods such as meats. It’s also best to eat them after being well soaked, rinsed and sprouted (ideally) to be easier to digest.
As the name suggest, these foods are low in starch. Examples of non-starchy vegetables are: asparagus, leafy greens, broccoli, celery, sprouts, cabbage, cucumbers, cauliflower, carrots, red radish, bok choy, lettuce, green beans, garlic, beetroot/beets, fennel, onions, chives, turnips, yellow squash, zucchini, and sea vegetables like kelp.
Fat and oil combinations
Organic, cold pressed unrefined and extra virgin oils, like olive or coconut oils, are great oils that combine well with all vegetables, grains and protein. But do avoid large amounts of fat with protein (like mayonnaise or aioli) because it slows digestion. Oil-free dressings work well, as does a small amount of oil, such as olive oil, mixed with lemon juice.
Protein fats occur where nature combines proteins and fats together (e.g. avocadoes, olives, seeds and nuts). Protein fats combine well with non-starchy vegetables and sour fruits like lemons, limes, fresh unsweetened pomegranates, or fresh/frozen unsweetened cranberries.
It’s best to soak nuts and seeds for easier digestion as nuts and seeds have a natural enzyme inhibitor coating to stop them from germinating, but this protection also inhibits our digestion. Soaking, sprouting or fermenting makes these foods more digestible and the nutrients more bio-available.
Fermented foods and drinks
Fermented foods and drinks like coconut kefir, coconut yoghurt, sauerkraut, fermented vegetables and fermented nuts and seeds (made into foods like cheeses and sour creams) are packed with vitamins, minerals and healthy micro-flora. They also feed friendly bacteria, help to heal the digestive system and leaky gut, and are easy to digest, which means that they combine well with any foods, even fruit.
The only times fermented foods are contra-indicated are if you have an allergy or intolerance to any of the foods they are made from or if you have a histamine intolerance or high histamine levels. High histamine is seen in conditions such as allergy reactions like hay-fever, asthma, sinus or rashes. Some people who suffer migraines may also have histamine intolerance (even without the presence of allergies). The way to find out is to get your histamine levels tested, or see if you react to any of the fermented foods or gut healing foods like bone broth, sauerkraut, jellies or yoghurts.
Reactions can be an intensification of any existing symptom, such as rashes or headaches, but in a nutshell, if you feel worse rather than better from eating fermented foods then you have an issue with histamine in food. This is usually temporary until your gut has healed by eating good food combinations (without fermented foods). Sometimes herbal antimicrobials are needed, and time. See your health practitioner for help.
Once symptoms abate, then very small amounts of fermented foods can be introduced, to gradually feed your good bacteria without causing distress e.g. just a few strands of sauerkraut, or just the juice from the jar of fermented vegetables, or a few sips of kefir, or a spoonful of dairy free yoghurt etc.
The main reason for the reactions is usually because there are too many of the wrong type of bacteria in the small intestine – see the information about SIBO – small intestine bacterial overgrowth in the SIBO Diet article. The foods that normally feed the good bacteria also feed the bad bacteria, which creates havoc in the digestive system. Reactions to probiotic supplements occur for the same reason with SIBO. Talk to your health practitioner if you have concerns about this.
Not the real name*
Melissa* came to me suffering from all sorts of complaints including gas, bloating, constipation, headaches, menstrual pains and brain fog. Initially we checked to see if she had any parasites or SIBO and any imbalance in her good and bad bacteria.
We found a few things that were treated with the SIBO diet and a treatment plan which eradicated her bad bacteria and parasites, and we re-established good bacteria with probiotics into her digestive system. During the treatment, she felt much better and her symptoms almost vanished, but as soon as she reintroduced some of her ‘normal healthy foods’ into her diet, many of her symptoms returned.
Rather than just getting a list of foods Melissa ate, I asked her to compile a food and symptoms diary so I could get a better idea of what was going on. When I saw the diary, her issues became obvious.
Melissa was combining fruit with proteins and carbs by adding fruit (mango or grapes) to chicken or salmon salads. Sometimes she had fruit for dessert after a meal; other times she had rice with protein meals such as in curries and stir-fries.
Now while many people eat this way and don’t seem to have any issues, for Melissa this was disastrous and no doubt triggered her gut bacteria imbalance in the first place. The unhealthy gut also affected her hormones and the fermentation gave her the headaches and brain fog.
The first trial was to keep the same foods in her diet, but to eat those foods at separate times, according to the food combining principles. Within only three days (which would have been after the previous foods had cleared from her system) Melissa found that she had no symptoms at all. She could continue to eat all her favourite foods, provided they were in the right order and combinations.
No more food trials were needed…Melissa ‘nailed it’ first time, once she knew what to do.