Food combining: How to combine foods for the best nutritional benefits

Food combining is one of the principles of a naturopathic diet and it involves combining certain foods together to improve digestion and nutrient absorption.

It is based on the concept that certain foods work well together and digest better. Foods that are improperly combined are harder for the body to digest.

Eating a ‘mixed meal’ (foods that don’t combine well) will leave partially digested food in your system while the other foods are being digested.

During this waiting period, the partially digested food will ferment in your digestive tract and contribute to digestive discomfort and toxic build-up.

What is food combining?

Dr Hay, a New York physician, began developing the food combining diet in 1904, because of his own poor health.

He determined that proteins and starches required different conditions for digestion. If consumed together, digestion time was slowed and nutrient absorption impaired.

Processed foods were also replaced by whole foods, along with increased fruit and vegetables.

This concept of eating was later called the Hay diet, which proposes three food categories – proteins, starches and neutral foods.

The idea of food combining can be compatible with a vegan diet, and is based on these basic principles:

• Proteins need an acidic environment to be digested (the stomach).
• Starches need an alkaline environment (the small intestine).
• Proteins take longer to digest than starches. If eaten separately, digestion is more efficient and less burden on the digestive system can be expected.

4 rules for food combining

1. Proteins must be eaten separately from starches

Starches such as potatoes, pasta, bread, rice, other grains should be eaten separately as protein is harder for the body to break down and it digests much slower than starches. This only applies to concentrated proteins (which include meat, fish, cheese, eggs and vegan meat alternatives.) Separate protein from starch meals by 3-4 hours.

2. Neutral foods can be eaten with protein or with starches

This includes non-starchy vegetables, herbs, oils, nuts and seeds.

3. Fruit should be eaten on its own

Fruits (especially melon) should be consumed on an empty stomach, as they digests more rapidly than other foods. This is due to its high water content and the simple sugars that fruit contains. Fruits and vegetables have different biochemical structures and break down at different stages of digestion.

Problems such as bloating and flatulence can occur when the breakdown of fruit is slowed down by the presence of other food. The exception is juicing, where low starch vegetables (celery, leafy greens and cucumber) can be combined with fruit, except sweet fruit. Do not combine acidic fruit (citrus, kiwi fruit, tomatoes, pineapple) with sweet fruit (bananas, figs, grapes, dates).

4. Avoid drinking cold water or fluids during meals

Try to limit your fluid intake before meals, or for at least one hour after eating, to prevent disrupting the digestive process.

Plant-based food groups

• Starches – potatoes, root vegetables, grains, beans and pulses. This includes butternut squash, sweet potatoes, yams, avocados, white potatoes, beetroot, parsnips, turnip, wheat, bread, pasta, rice, oats, rye, millet, buckwheat, quinoa, amaranth, spelt, corn, peas, chickpeas, butter beans, navy beans, black beans, cannellini beans, haricot beans, lentils, split peas.
  Even though beans, lentils and chickpeas are a blend of plant-based protein and starches, they are more starch-based than protein (about 30% protein). These foods are best used as a basis for starch-based meals rather than a protein-based meal, such as a vegan bake or bean and vegetable soup.
• Vegan proteins – soya, Quorn.
• Fats – oils, butter, nuts, dried and fresh herbs and spices are also considered ‘neutral’ foods and can be combined with either group.
• Non-starchy vegetables – aubergine, Chinese cabbage, parsley, asparagus, courgettes, peppers, beansprouts, cucumber, red cabbage, beans, fennel, radishes, bell peppers, garlic, rocket, bok choy, green beans, savoy cabbage, broccoli, ginger, spinach, Brussels sprouts, kale, spaghetti squash, carrots (raw), lettuce, Swiss chard, cauliflower, mangetout, tomatoes, celeriac, mushrooms, white cabbage, celery, onions and watercress.

Food combinations to promote nutrient absorption

Fat-soluble vitamins

• Some vegetables contain fat-soluble vitamins like A and K, which means they need to be consumed with healthy fats in order to be absorbed properly.
• Orange vegetables, such as carrot, butternut squash and sweet potatoes contain vitamin A.
• Green vegetables, such as kale, broccoli, collard greens, cabbage, lettuce and spinach are high in vitamin K.
• Good fat sources to eat with these vegetables include avocado, extra-virgin olive oil, flaxseeds and chia seeds.

Vitamin C and iron-rich foods

• The absorption of iron is enhanced by vitamin C, so eating iron-rich foods with foods that are high in vitamin C is recommended.
• Plant-based sources of iron include beans, leafy green vegetables, broccoli, dried figs and apricots.
• Vitamin C can be found in most fruits and vegetables, such as citrus (oranges, lemons, grapefruit), peppers, strawberries, kiwi, broccoli, Brussels sprouts, spinach, cabbage, sweet potatoes, white potatoes, tomatoes and butternut squash.

Turmeric and black pepper

• Turmeric is a wonderful herb that helps to protect cells from damage, reduce inflammation, promote healthy skin, improve cardiovascular function and balance an overstimulated immune system¹.
• Black pepper contains a compound called piperine, which aids the absorption of curcumin, the medicinal component of turmeric that has anti-inflammatory properties.
• Adding some black pepper to dishes that contain turmeric increases the amount of curcumin your body absorbs by 2000 per cent.

Food combinations to avoid

These food combinations may negatively affect nutrient absorption.

• Coffee and calcium-rich foods
  Caffeine can reduce calcium absorption. Drinking coffee near to consuming calcium-rich foods like almonds, dark green leafy vegetables, cauliflower, beans and dried figs can be detrimental to your health.
  Coffee is also highly acidic and irritates the gut, causing inflammation, reduced mineral absorption and lowered stomach acid production.
• Tea and iron-rich foods
  There is a compound in tea called phytates that competes with iron for absorption. In other words, tea can block iron absorption so it’s best to avoid drinking tea a few hours either side of eating iron-rich foods.

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Featured photo © Yulia via Adobe Stock

References:

1. Hewlings SJ, Kalman DS. Curcumin: A Review of Its Effects on Human Health. Foods. 2017 [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5664031/]