Diet & Nutrition

What Is Food Combining? | Nutrition Stripped

How the food combining trend started, what it includes and the impact it may have on your body.

Are there certain food items we need to eat alone as opposed to alongside others? Should we be concerned about the combinations we’re creating on our plates? What is food combining?

These are the questions we’re frequently hearing from the NS Community, so let’s chat about them.

Food Combining

If you’re up to date on social media trends and following along with wellness bloggers and influencers, chances are you’ve heard of ‘food combining’ in recent months.

In it’s most basic form, the food combining diet suggests that certain food items should be eaten alone while others should be paired in a particular way. This is recommended in order to supposedly prevent digestive issues, heal gut issues, improve immune function, and promote weight loss.

When phrased this way, some of this may sound familiar. We’ve definitely discussed the pairing of certain macronutrients with others to allow for optimal digestion here at NS. But don’t be confused, this is something altogether different (more on that later).

The Rundown On Food Combining Theory

The food combining diet is made up of a list of principles based on three major components: pH levels, enzymatic activity, and the rate of digestion.

So what do those components entail?

The principles are based on the idea that different macronutrients require specific pH levels in order to be digested properly. More specifically, protein requires an acidic environment while carbohydrates require an alkaline environment.

The food combining diet also believes that because different macronutrients require different enzymes for digestion, we should refrain from combining certain macronutrients in one meal — particularly protein and carbohydrates.

It additionally suggests that when food items requiring opposing pH levels and different enzymes are consumed together, the slower-digested food items hang back in the gut longer causing issues and poor nutrient absorption. Issues could include gas, bloating, weight gain and possibly a build-up of toxins.

Food Combining Principles

With all of this in mind, the food combining diet essentially comes down to 5 major principles:

  1. Always eat fruit on an empty stomach
  2. Never eat protein with carbohydrates
  3. Eat carbohydrates alone or with cooked non-starchy vegetables
  4. Consume protein alone or with cooked non-starchy vegetables
  5. Consume dried fruit, nuts and seeds with raw vegetables

What Does The Science Say About Food Combining?

There has only been one viable study testing the claims made by the food combining diet. The study found that there were no benefits to food combining that a balanced, low-calorie diet didn’t already provide (1).

There currently isn’t any reliable research proving the validity of the food combining diet claims or its principles.

When we look at the research we do have on macronutrients and digestion, there are quite a few components of food combining that just don’t add up.

Let’s Talk Digestion

Now that we know the food combining principles and the rationale behind them is, let’s strip down these principles and explain why we really shouldn’t be following them.

“Always eat fruit on an empty stomach”

The food combining diet believes that because fruit digests very quickly, it should be eaten alone on an empty stomach. The rationale here is that when fast-digesting food items are combined with other food items that digest slower, the fruit gets “stuck” in the digestive tract for a longer period of time than it should.

The problem with this take is that food can’t really get “stuck”. Whenever we eat, our body produces enzymes in response to digest our food accordingly. Amylase is the enzyme responsible for carbohydrate digestion, protease for protein and lipase for fat digestion. Regardless of what other macronutrients are present, our body will always send out amylase to help digest carbohydrates when necessary.

Moral of the story, there is no need to consume fruit on its own. Fruit will be digested just fine when combined with other food items!

“Never eat protein with carbohydrates”

This principle is based on the fact that carbohydrates need an alkaline (or basic) environment to be digested, while protein requires a more acidic environment.

The problem with this statement is that the stomach itself has an acidic environment, and for good reason too! When we eat any food item, not just carbohydrates, the stomach is signaled to release gastric acid. The acidity is meant to kill any bacteria in the food before allowing it to move on to the small intestine.

Whether carbohydrates are consumed alone or with protein, they’re still going to enter an acidic environment. And that is perfectly fine! After the food passes through the stomach it enters the small intestine, a more alkaline environment. This is where the majority of carbohydrate digestion occurs.

So, are carbohydrates better digested in an alkaline environment? Yes. Does the presence of protein interfere with this process? No.

“Eat carbohydrates alone or with cooked non-starchy vegetables”

While we can definitely get on board with pairing non-starchy vegetables with carbohydrates (hello, fiber!), we don’t recommend always consuming carbohydrates on their own.

Eating carbohydrates alone isn’t the best for our blood sugar. Carbohydrates are the body’s preferred source of energy, which allows them to be digested very easily. Therefore, when eaten alone, they can cause a spike in blood sugar followed by a subsequent drop. Frequent spikes and drops like these can mess with our hunger cues, cause insulin resistance over time and possibly lead to an excess of fat storage as well.

We’re much better off pairing our carbohydrates with protein or fat as opposed to consuming them alone. Consuming protein and fat alongside carbohydrates curbs the rate of glucose absorption and therefore prevents a spike in our blood sugar. This will keep you full longer and help prevent the development of insulin resistance over time.

“Consume protein alone or with cooked non-starchy vegetables”

Realistically, we have no issues with this principle. There are no concerns with consuming protein alone or with non-starchy vegetables.

When it comes to cooked versus raw vegetables, this all depends on your particular digestive system. If you don’t have any preexisting conditions that inhibit you from digesting fibrous food items regularly, raw vegetables are perfectly fine. Sticking to cooked vegetables for the majority of the time is only necessary if you have been diagnosed with gastroparesis or any other condition requiring a low-fiber diet.

For the same rationale we gave when we debunked principle number two, don’t be scared to have protein with fat or with carbohydrates. Our bodies are made to multitask, they can handle it!

“Consume dried fruit, nuts and seeds with raw vegetables”

Once again, there isn’t any evidence proving the need for this principle. Of course, pairing vegetables with anything is great! But there is no need to refrain from eating nuts and seeds without them. Nuts and seeds can be consumed alone without any concern for blood sugar because they are sources of both protein and healthy fat.

Dried fruit, on the other hand, is a potent carbohydrate, it simply has a lot of sugar per portion size. By pairing it with a protein or fat source, we can help slow down digestion to avoid a blood sugar spike. While adding some vegetables in there can’t hurt, protein and fat will do a much better job at slowing things down.

How Did Food Combining Start?

In order to really understand what the food combining diet is, we need to understand where it came from. Although the food combining diet has become quite popular in recent months, it really isn’t anything new.

Food combining has roots in Ayurvedic medicine, an ancient practice dating back over 5,000 years. Additionally, the Hay Diet is one of the earliest versions of the food combining diet. William Howard Hay, the creator of the diet, was a physician in the 1920s looking to cure his own physical ailments. His diet strongly resembles that of the food combining diet today.

Bottom Line

Despite the fact that principles of the food combining diet have been around for quite some time, the science just doesn’t support it.

What the science does support is a well-rounded, whole food diet made up of food combinations galore! The body is ready and able to digest all of the macronutrients. Food combinations are what promote optimal nutrient absorption, GI transit, and overall digestion.

When it comes to emerging diets and trends, always look to science. Regardless of who supports it or how many wellness bloggers endorse it, a diet is a diet all the same.

We’re all about personalization of nutrition, how you eat and finding a way that uniquely works for your body and lifestyle. Healthy living has to be a lifestyle, not a diet. Diets always have an end date, lifestyles, on the other hand, do not.


Had you ever heard of the food combining diet before? Have you tried it? We would love to hear your thoughts on the trend, and I’m sure someone else reading the article would as well! As always, you can connect with us on Instagram @nutritionstripped @nutritionstrippederica and #nutritionstripped #nswellnesscoaching.

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