In this article and video we will explore why fruit can be easier to digest than other foods by understanding several aspects of digestive physiology.
There are three macronutrients that we find in whole foods: carbohydrate, protein, and fat. Fruit is high in carbohydrate and in general, carbohydrates tend to be more quickly digested than protein and fat.
Here is a chart that illustrates the carbohydrate, protein, and fat content (as a percentage of calories) of various types of foods:
|Type of Food
|Nuts and Seeds
As we can see, the macronutrient content of fruit averages 89% carbohydrate, 6% protein, and 5% fat. Fruit is the highest in carbohydrate of the food groups listed.
Types of carbohydrates
There are three different types of carbohydrates: polysaccharides, disaccharides, and monosaccharides. Monosaccharides are composed of a single sugar, as the name would imply. Mono means “one” and saccharide means “sugar”. Disaccharides are two monosaccharides hooked together by a chemical bond. Polysaccharides are composed of multiple monosaccharides hooked together by chemical bonds. For further clarification, there are two types of polysaccharides, digestible and non-digestible. An example of a digestible polysaccharide is starch and a non-digestible example is fiber. Starch is also referred to as “complex carbohydrate”, while fiber is also known as “cellulose”.
Complex carbohydrates, such as starch, and disaccharides have chemical bonds that must be broken down by digestive enzymes into monosaccharides in order to be absorbed. The human body uses the carbohydrate-digesting enzyme amylase to break down complex carbohydrates into simpler carbohydrates. A common disaccharide is sucrose, which is composed of glucose and fructose hooked together by a chemical bond. Since sucrose is a disaccharide, it is broken down by the digestive enzyme sucrase into the monosaccharides glucose and fructose, which can then be absorbed.
To summarize, monosaccharides are absorbed by our digestive tract, so carbohydrates that are more complex must be broken down into monosaccharides in order to be absorbed.
Carbohydrates in fruit
The carbohydrates found in fruit are primarily fructose and glucose, both of which are monosaccharides, so they do not need to be broken down further by digestive enzymes. This is a reason why fruits are often referred to as being “predigested”. In other words, our body absorbs fructose and glucose “as is”, without using digestive enzymes to break them down further.
Here is a chart showing the fructose, glucose, sucrose, and complex carbohydrate content of various fruits:
||Complex carbohydrate (g)
|Mango – one whole (207 g)
|Blueberries – one cup (148 g)
|Cantaloupe – 3lbs. (1360 g)
|Apricots – one cup sliced (165 g)
|Figs – 5 dried
|Raspberries – 1 cup (123 g)
|Strawberries – 1 cup sliced (166 g)
|Apples – one medium (182 g)
|Watermelon – One cup diced (152 g)
|Grapes – One cup red (151 g)
|Pineapple – One cup chunks (165 g)
|Banana – one medium (118 g)
The fructose and glucose content of these fruits is notable, especially when compared to the complex carbohydrate content, which is in several cases quite a bit lower. The sucrose content of these fruits varies by type of fruit.
This next chart shows the carbohydrate content of other various other plant foods:
||Complex carbohydrate (g)
|Bell pepper – 1 cup chopped red (149 g)
|Tomatoes – One cup chopped (180 g)
|Carrots – One cup chopped (110 g)
|Lettuce – 4 cups shredded (188 g)
|Yam – One whole (130 g)
|Lentils – ½ cup (96 g)
|Brown rice – med grain, ½ cup (95 g)
The yam, lentils, and brown rice on this table contain much more complex carbohydrate than the fruits we examined in the previous table. These foods are also generally much lower in glucose, fructose, and sucrose than the fruits. This would suggest that yams, lentils, brown rice and other foods high in complex carbohydrates would require more digestive enzyme activity than fruits, which contain simpler carbohydrates. Vegetables, such as carrots and lettuce, are in a less extreme but similar category since they contain fewer simple carbohydrates and generally more complex carbohydrates than most fruits.
In summary, the higher simple carbohydrate content, lower complex carbohydrate content, and lower protein and fat content of fruit versus other foods may account for the reason why the digestion of fruit requires less digestive enzyme activity than other foods. This ease of digestion and simple carbohydrate content constitute at least part of the reason why fruit can provide us with quick energy for our daily activities, and perhaps even our natural detoxification and healing processes. I look forward to a time when more information is available to share with you on this fascinating topic!
Isn’t fruit controversial for some reason?
To make it easy for people to find reliable information on fruit, the glycemic index, glycemic load, fructose, glucose, and carbohydrates in general, we dedicated a chapter in our book, The Raw Food Nutrition Handbook: An Essential Guide to Understanding Raw Food Diets to answering many common carbohydrate questions.
In the book we also cover other hot topics in raw food nutrition such as essential fats, protein, nutrient content of raw food diets, food combining, enzymes, hydration, vitamins, minerals, and many more. We value education on these important topics and are happy to finally bring this book to you. The book is available on Amazon and other online booksellers.
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