Food combining – Facts and fallacies

By February 19, 2011Nutrition

Food combining is controversial. Some say it’s a load of rubbish. Others swear by it. Could it be that, fifty years on, Dr Hay’s food combining theories need an update?

The fact that the very words ‘food combining’ sell, strongly suggests to me that the experience of many people tells them that certain types or combinations of food don’t suit them. That too is my experience. Dr Hay devised a set of rules that have helped millions of people. But are all the rules right? A ‘food combiner’ is not only combining food differently, they’re also eating different kinds of food, and may even be eating less food because of the practical constraints of eating to a set of rules. How do we know whether the advantages are due to food combining or these other factors?

The key elements in Dr Hay’s original theory, expounded in the 1930s, was to eat ‘alkaline forming foods’, eat fruit on its own, avoid refined and heavily processed foods, and not mix protein rich and carbohydrate rich foods.

Protein and carbohydrate are digested differently. That is a fact. Carbohydrate digestion starts in the mouth when the digestive enzyme amylase , which is in the saliva, starts to interact with the food you chew. Once you swallow food and it enters the relatively acid environment of the stomach, amylase stops working. Only when the food leaves the stomach, where the digestive environment becomes more alkaline, can the next wave of amylase enzymes, this time secreted into the small intestines from the pancreas, continue and complete digesting carbohydrate.

Protein, on the other hand, is not digested at all in the mouth. It needs the acid environment of the stomach and may hang out there for 3 hours until all the complex proteins are broken down into small groups of amino acids. This only happens in the stomach because of high levels of hydrochloric acid which is needed to activate the protein digesting enzyme, pepsin. Once small groups of amino acids leave the stomach they meet peptidase enzymes, again from the pancreas, which break them down into amino acids, ready for absorption.

The Myth of the bean

The overly simplistic understanding of food combining is to separate carbohydrate and protein foods because they are digested differently. The fact that eating certain kinds of beans produces flatulence is often quoted as a negative effect because beans are both protein and carbohydrate. However, it is now known that this is not the reason for beans’ boisterous reputation. In some beans there is a kind of protein which cannot be digested by the enzymes in our digestive system, even when eaten alone. This protein can, however, be digested by the bacteria that live in the large intestine. So when you eat beans you not only feed yourself you also feed these bacteria. These bacteria produce gas after a good meal of lectin, hence the flatulence. It’s got nothing to do with food combining. This makes sense to me since many healthy cultures throughout the world have evolved to eat a diet in which beans or lentils are a staple food.

Protein & Carbohydrate – foods that fight?

Of course, since food isn’t either exclusively carbohydrate or protein, in practical terms separating protein and carbohydrate means not combining concentrated protein foods with concentrated starch foods. Certain foods contain more protein, others, more starch. So where exactly do you draw the line, if a line should be drawn at all?

A brief excursion into our primitive past may solve the puzzle. The general consensus is that we, the human race, have been eating a predominantly vegetarian diet for millions of years, with the occasional meat or fish. Monkeys can be divided into two types: those who have a ruminant like digestive tract and slowly digest even the most indigestible fibrous foods, much like a cow; and those who have a much speedier and technologically advanced digestive system producing a whole series of different enzyme secretions. We fit into the second category. The system is more efficient but can only handle foods that are easier to digest – fruit, young leaves, certain vegetables – no stalks for us! Evolutionary theorists believe this ‘latest model’ digestive system did two things: firstly, it gave us the motive to improve mental and sensory processing so we would know when and where to find the food we needed, and secondly, it gave us the nutrients to make a better brain, and nervous system.

Did monkeys eat fruit & two veg?

I believe we have three basic programmes for food digestion. The first is for digesting concentrated protein. In reality this means meat, fish and eggs. To digest these foods we have to produce vast amounts of stomach acid and protein digesting enzymes. After all, if our ancestors had hunted down and killed an animal do you think they then went off to hand pick a few tasty morsels of vegetation to create that ‘balanced meal’? I doubt it. I imagine they ate their catch, organs and all, as fast as possible before it went off and other predators moved in, perhaps having a couple of days on nothing but concentrated animal protein. Fresh, raw, organic meat is, after all, highly nutritious.

Fruit – the lone ranger
At certain times of year we would have had access to certain fruits. No doubt we weren’t the only fruit-eating creatures. Since fruit is basically the best fuel for instant energy, requiring very little digestion, we have a simple programme for producing the enzymes and hormones necessary to process the simple carbohydrates in fruit. Again, my guess is that we mainly ate fruit on its own. After all, once you’ve chomped three bananas there’s little motive to go digging up a few vegetables.

Many kinds of soft fruits ferment rapidly once they’re ripe. If you stick them in a warm, acidic environment, which is what the stomach is, they’ll ferment rapidly. That’s what happens if you eat steak and a melon in close succession. So Dr Hay’s advice to eat fruit separately makes a lot of sense. Since fruit takes around 30 minutes to pass through the stomach, and concentrated protein takes 2 to 3 hours, this means that the best time to eat fruit is as a snack, more than 30 minutes before a meal, or not less than 1 to 2 hours after a meal, and possibly more if you eat a lot of concentrated protein. The only exception to this is combining fruits that don’t readily ferment, like bananas, apples or coconut, with complex carbohydrate rich foods such as oats, or millet. So apple porridge or a whole rye banana sandwich would be fine.

I believe that, most of the time, our ancestors ate a varied vegan diet. That means leaf vegetables, root vegetables, nuts, seeds, pulses and sprouts. This, I propose, is the third and most common digestive programme – a mixture of foods containing a mixture of carbohydrate and protein, but never as protein dense as meat. I don’t see any problem in combining rice, lentils, beans, vegetables, nuts and seeds.

Refined carbohydrates are out

Not only is refining food a modern invention, so too is cooking it. Dr Hay recommended neither. The more refined, processed or cooked a food is the less nutrition it will provide. But, apart from the obvious advice to eat raw or lightly cooked whole foods, instead of overcooked and over processed junk foods, refined high sugar foods is a new invention as far as your digestive system is concerned. Very few naturally occurring foods contain the kind of concentrations of fast-releasing sugars that modern food can provide. The body is simply not adapted to deal with a flood of fast-releasing sugars which not only make blood sugar levels rocket, requiring all sort of hormones to swing into emergency action to restore the balance, but also feed potentially undesirable micro-organisms that can occur in the gut.

In a nutshell, I believe that food combining can be condensed into five simple steps, shown below. If a person still has digestive problems dealing with these food combinations they may have either a digestive problem, a food intolerance or a gut infestation of candida or unfriendly bacteria and should see a nutritionist. Vegans only have one rule to follow, which is to eat certain fruits separately. Simple, isn’t it?

The new food combining – Five steps to better digestion

  • Eat 80% alkaline forming foods, 20% acid forming foods. This means significant vast quantities of vegetables and fruit, and less concentrated protein foods like beans, lentils and wholegrains, instead of meat, fish, cheese and eggs.
  • Eat fast fermenting and acid fruits on their own as snacks. Most soft fruits ferment quickly. These include peaches, plums, mangoes, papayas, strawberries and melons. High fruits (although alkaline forming) may also inhibit digestion of carbohydrate. This includes oranges, lemons, grapefruit, and pineapple. All these fruits require little digestion, releasing their natural fructose content quickly. Eat them on their own as a snack when you need an energy boost.
  • Eat animal protein on its own or with vegetables. Concentrated protein like meat, fish, hard cheese and eggs require large amounts of stomach acid and a long stay in the stomach (around 3 hours) to be digested. So don’t combine fast-releasing or refined carbohydrates or food that ferments with animal protein.
  • Avoid all refined carbohydrates. Eat unrefined, fast-releasing carbohydrates with unrefined slow-releasing carbohydrates. Fruits that don’t readily ferment, such as bananas, apples and coconut, can be combined with slow-releasing carbohydrate cereals like oats and millet.
  • Don’t eat until your body is wide awake. Don’t digest when your body is asleep. Leave at least an hour between waking and eating. If you exercise in the morning eat after this. Never start your day with a stimulant (tea, coffee, cigarette). The ‘stress’ state inhibits digestion. Eat only carbohydrate based breakfasts such as cereal and fruit, just fruit, or wholegrain rye toast.

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