Have you ever heard about the Combining Food Diet?

Have you ever heard about the Combining Food Diet? If not, fear not. The first time I heard about this diet was actually at a job interview I went to recently (not the best place to find out something new, I know). My potential employer sat across the table from me, excited about the prospect of us working together, until she mentioned that their previous nutritionist used to put clients on the Combining Food Diet. She asked me if I used this diet approach as well. I had actually never heard of this dietary approach before, even throughout my studies. When I got home that day, I did some research and was quite amazed at what this diet was all about. It just didn't make sense compared to what I'd learnt in my degree about digestion.

Curious to find out where this diet came from and, more importantly, the science behind it, I set out to find some research. Here is what I found.

What is this diet all about?

The Combining Food Diet is based on the principle that certain foods need different environments in order to digest well. If the environment is not correct, the foods are thought to sit in the stomach for long periods of time, during which they rot.

Yes, you read that correctly- they rot.

From the above picture one thing is certain- there are a bunch of rules that need to be followed in this diet. If you are also staring blankly at this picture like I did, then let me simplify the three main rules for you:

Fruit and milk must be eaten on an empty stomach and at least 3 hours before / after other foods.
Starchy vegetables and grains must be eaten with non-starchy vegetables only.
Meat, chicken, fish and eggs must be eaten with non-starchy vegetables only.

The scientific explanation given for these rules is that the enzymes needed to breakdown carbohydrates require an alkaline environment in order to work. Therefore, if acidic foods (fruits or proteins) are eaten at the same time, their acidity is thought to denature these enzymes, preventing the starches from digesting.

This all sounds pretty legitimate, right? For a person who hasn't studied the digestion process in detail, this explanation does sound quite scientific and logical.

But from a dietitians point of view, however, there are a few major problems with this theory.

What happens when food enters the stomach?

As food reaches the stomach, it hits a welcoming pool of stomach acid (HCl). HCl has a very low pH, which kills any harmful bacteria or pathogens. It also begins to breakdown proteins. The stomach then churns all the food together (carbohydrates, protein and fat) into a big mush, known as chyme.

When the chyme is ready, it moves down into the small intestine. This usually happens about 4 hours after eating. As you can imagine, at this stage the chyme is just all one pH and one entity. There are no separate foods leaving the stomach.

Here in the small intestine, enzymes get released to further digest carbohydrates and fat. These enzymes do need a slightly alkaline environment to work, so bile is released to neutralize the acidity of the chyme.

As you can see now, the whole theory of the Food Combining Diet doesn't make sense from this point of view.

But I've heard of people who have found success on this diet. How does that work?

There is quite a simple explanation for this really. Let's take a look at an example of a day's intake on this diet.

Breakfast: Scrambled eggs with 3 slices of bacon and grilled tomato.

Mid-AM snack: Bowl of fresh, plain, chopped fruit.

Lunch: Plain wholegrain pasta with non-starchy vegetables.

Mid-PM snack: Banana.

Supper: Steak with non-starchy vegetables.

If you look closely, you'll see that there is a food group missing at each meal. This makes it nearly impossible to take in all the portions of food groups that the body needs in one day.

A deficit of food would naturally result in weight loss, however, this would also cause a deficit of nutrients. This means that our body would be missing out on all the nutrients, vitamins and minerals it requires in a day.

Another major downside of this diet is that it is not easy to maintain. The strict rules of this diet are very difficult to follow for long periods of time. This means that the risk of regaining weight is very high.

So what is the conclusion?

The Combining Food diet may sound very convincing, but it isn't actually based on proper science. It may result in quick weight loss, but it doesn't give the body all the nutrients it needs. This can lead to relapse back into old dietary habits and weight gain.

The goal of weight loss is not just to lose weight, it is to improve your overall lifestyle. This requires sustainable changes that you will be able to maintain for the rest of your life. You want to eat in a way you that you'll enjoy and be able to continue. See my nutrition basics page for more information.

I hope you found this article informative. Please share it with your friends and give me feedback on which topic you'd like me to write on next!