What Is Food Combining? Facts And Details

Food combining is a popular diet idea. It claims that eating certain food groups together, such as starches and proteins, harms digestion, and that eating them separately helps you digest better and lose weight.

Does it hold up? In short, no. Your digestive system is built to handle mixed meals, and a well-known study found food combining was no better for weight loss than a balanced diet.

What Is Food Combining?

Food combining is a set of rules about which food groups you can eat together. Its followers believe that the wrong combinations lead to disease and digestive distress.

For example, food-combining rules say steak with a potato is a bad pairing, because it mixes protein and starch. There is no good evidence that this pairing causes disease.

Food Combining

The idea is old. Ayurvedic medicine has long had guidance on which foods to eat together. In the 20th century, the idea was popularized in the West, including under the name "trophology."

In the 1900s, the Hay diet made this method popular, and it still shows up in some modern diets. Generally, food-combining diets sort foods into groups.

These are usually broken down into carbohydrates and starches, dairy, fruits, vegetables, and proteins. Some plans also classify foods as acidic, alkaline, or neutral.

Proponents say that different foods digest at different speeds. They claim that combining a fast-digesting food with a slow-digesting one causes a "traffic jam" in your digestive tract. and leads to poor digestion and health. As the sections below explain, the science doesn't support this.

Food-combining diets tell you how to combine these groups in a meal. Let’s have a look at the rules of food combining.

Rules of Food Combining

These laws of food combining vary depending on the source, but the most common rules are:

Eat fruit on an empty stomach.
No combination of starches and proteins.
No combination of starches with acidic foods.
Don’t combine different types of protein.
Only consume dairy products on an empty stomach, especially milk.
Proteins should not be mixed with fat.
Sugar should only be eaten alone.
Fruits and vegetables should be eaten separately.

According to science:

Only a small amount of research has tested food combining directly. The best-known trial, published in the International Journal of Obesity in 2000, put 54 adults with obesity on either a food-combining diet or a balanced diet for 6 weeks.

Both groups ate the same number of calories, 1,100 per day. Both lost similar amounts of weight, about 6 to 7.5 kg on average, and the food-combining diet gave no extra benefit. In other words, food combining is no better than a balanced diet with the same calories.

Avoiding mixed meals:

Many foods naturally contain a mix of fat, carbs and protein, and your digestive system handles these meals easily. When food enters the stomach, it releases acid and the enzymes pepsin and lipase, which start breaking down protein and fat.

These are released whether or not a meal contains protein or fat.

Then food moves into the small intestine. The stomach acid is neutralized, and the intestine releases enzymes that break down proteins, fats and carbs at the same time.

Our digestive system is a multitasking organ.

The pH of the Digestive Tract

Another belief in food combining is that eating foods with the "wrong" pH together harms digestion. pH is a scale that shows how acidic or alkaline something is. Different digestive enzymes work best in different pH ranges.

However, the acidity of your food doesn't throw off your digestive tract. Your body keeps the pH of each part of the digestive tract in the right range on its own.

The stomach's low pH is important because it helps start protein digestion and activates stomach enzymes. It also helps kill bacteria in your food.

When a meal is more acidic or alkaline, your body simply adjusts the amount of digestive juices to reach the right pH.

Food Fermenting in the Stomach

Food-combining fans also say that improper combinations make food ferment or rot in the stomach.

It does not happen.

Fermentation occurs when microorganisms break down food. The stomach is so acidic that very few bacteria can survive there, so food doesn't ferment in it.

Fermentation does happen in the large intestine, where many beneficial bacteria live. This is normal and healthy, and it is linked to benefits such as lower inflammation.

Pairings That Actually Matter:

Some food pairings do affect how well you absorb nutrients, but often in the opposite direction from food-combining rules:

Citrus fruits and iron: this is a helpful pairing. According to MedlinePlus, foods rich in vitamin C, such as citrus, strawberries and tomatoes, increase iron absorption from plant foods.
Carrots and fat: also helpful. Carrots are rich in beta-carotene, which the body turns into vitamin A, a fat-soluble vitamin, so a little fat in the meal helps you absorb it.
Spinach and dairy: this one has some truth. MedlinePlus notes that oxalic acid in spinach can bind calcium and reduce how much is absorbed. It isn't harmful, but don't rely on spinach as a calcium source, and get calcium from a variety of foods.

Best To Combine:

combining foods rich in vitamin C with plant sources of iron, such as beans or lentils
add some cheese or olive oil to your salad
top your broccoli with a little butter or olive oil

Conclusion:

Food combining is not scientifically based. The claim that improper food combining causes poor digestion and illness is not true, and research shows food combining is no better than a balanced diet. If you enjoy it and it helps you eat well, you can continue with it.

Because it has so many rules, food combining is not easy to follow, and there is no proof that it has any special benefit. If you have digestive symptoms, see your doctor rather than cutting out food groups on your own.

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