Food combining is a nutritional strategy that advocates eating specific foods at the same time and avoiding the intake of other specific food combinations.
The argument for food combining is based on the idea that different kinds of foods require different digestive processes. Thus, eating certain food combinations, specifically protein-rich foods with carbohydrate-rich foods, decreases absorption of nutrients, causes food to “sit and ferment” in the GI tract, which then leads to a build-up of toxins, finally causing a host of chronic diseases.
Where Does The Theory Of Food Combining Come From?
The practice of separating intake of specific foods has been around since ancient times (i.e. Kosher eating, where milk and meat can never be consumed together), but food combining for purposes of improved health is a newer concept. The Hay Diet, developed in the 1920s by a physician named William Hay, placed all foods into one of three groups: acidic, alkaline or neutral. He argued that combining acidic foods (protein-rich foods such as meat, fish and dairy) with alkaline foods (carbohydrate-rich foods like grains, potatoes and rice) causes a build-up of acidic end-products that are harmful to the body.
Other food combining plans cite the fact that protein-rich foods need acidic enzymes for digestion, whereas carb-rich foods need more alkaline enzymes, and eating the two at the same time cause the enzymes to “cancel each other out” and stops digestions and assimilation of nutrients.
Common “Rules” In Food Combining1
- Always eat fruit on an empty stomach or at least 20 minutes before eating anything else.
- Eat starches alone or with cooked, non-starchy vegetables
- Eat meat, dairy, fish and eggs alone or with cooked, non-starchy vegetables
- Eat nuts, seeds and dried fruit with raw vegetables
There are numerous slight variations from specific plan to specific plan, but they all essentially follow the above rules.
Is There Any Evidence That Food Combining Is Beneficial?
In short, there is absolutely no evidence that eating protein with carbs at the same time interferes with digestion of either. I did a pretty extensive literature search and was only able to find one peer-reviewed article that related to food combining.2 It examined the effects on weight loss of traditional versus a food combining diet. The authors found no difference in weight loss between the two approaches. Additionally, I found it odd that, at least according to some food combining advocates dried fruits should be grouped separately from fresh fruits. They argue that fruit should be eaten alone on an empty stomach due to its rapid absorption rate, yet dried fruit has an identical chemical make-up to fresh fruit but is absorbed more rapidly. Still, food combining proponents recommended that dried fruit be combined with other foods. This makes no sense to me.
Moreover, many fibrous vegetables have significant amounts of protein. For example, 3 ounces of raw broccoli has 2-3 grams of protein and 4 grams of carbohydrate. I would argue eating broccoli should cause the same issues as eating rice with meat according to the “enzyme cancellation” theory of food combining. I could not find any food combining sites that addressed this issue.
Are There Any Potential Benefits To Food Combining?
Food-combining diet proponents advocate non-processed, wholesome and nutritious foods. While this is not revolutionary by any means, it is a great way to eat. Should you chose to follow a food combining diet made up of these whole foods (which I do not recommend as I will discuss below) , you will probably feel much better than you would feel eating a “normal” diet – not due to the food combining but because of the types of food emphasized in the plan.
Should I Try A Food Combining Diet?
Nutrition plans must be maintainable and practical, and the rigid rules of food combining may be difficult for many people to practice in the real world. Additionally, as most people are looking to lose at least some body fat, reducing calories is a common goal. Eating carbohydrates alone (especially high glycemic load sources like bananas) often causes rebound hunger, as without protein and fat to slow absorption, there is a real risk of a rapid rise in blood sugar, an insulin spike followed by a drop on blood sugar and finally a strong feeling of hunger.
I recommend a nutrition plan based around whole, unprocessed foods, with each meal containing protein, unprocessed carbohydrates and healthy fats. This type of eating has been shown again and again to aid in losing fat and improving health and energy.