Fruit is Good for you, Right?

We've all been taught that we should eat plenty of "fruits and vegetables." Fruits and vegetables are rarely separated out in nutritional guidelines. They are separated but paired in the USDA food pyramid which recommends eating about equal parts "fruits" and "vegetables." (A more detailed version of current USDA recommendations can be found at mypyramid.gov and health.gov.) Parents are typically happy if they can get their children to eat lots of fruit juice and fruit products (typically with added sugar) when they won't eat much in the way of vegetables.

Even among those who are supposedly being more discriminating about their food choices, fruits are almost always treated as something to eat in large, if not unlimited, quantity. For example, the Paleo Diet, which attempts to recommend a diet alleged to be similar to that of our hunter-gatherer ancestors, recommends consuming "all the fruit and non-starchy vegetables you can eat." (You are warned against eating too much dried fruit—most fresh fruits are about 80–90% water, so removing most of the water can dramatically increase the total quantity you can eat. Similarly, some people warn against drinking too much fruit juice which is another way you can consume a lot more fruit very quickly.)

Fruits are alleged to be good for you, because they contain a lot of essential vitamins and minerals as well as fiber and such newer necessities as "phytochemicals" and "antioxidants." So what's really in fruit? Even those of us who habitually read nutrition labels tend to be unfamiliar with the nutritional content of most fruits, since, as typically sold fresh, there aren't any nutritional labels. The following table gives some data for a lot of common (and a few less common) fruits.

Fruit	Protein	Fat	Carb	Fiber	Sugar	Fructose	Glucose	Sucrose	Other		All based on 100 gm serving
Apple	0 g	0 g	13 g	1 g	10 g	6 g	3.2 g	0.8 g	7% C
Apricot	1	0	11	2	9	0.9	2.4	5.9	39% A, 17% C, 7% Potassium
Banana	1	0	23	3	12	4.9	5.0	2.4	15% C, 18% B6, 10% Potassium, 13% Mn
Blackberry	1	0	10	5	5	2.4	2.3	0.1	35% C, 32% Mn
Blueberry	1	0	14	2	10	5.0	4.9	0.1	16% C, 24% K, 17% Mn
Breadfruit	1	0	27	5	11				48% C, 7% Thiamin, 6% Mg, 14% Potassium
Cherry (sour)	1	0	12	2	8	3.5	4.2	0.8	26% A, 17% C
Cherry (sweet)	1	0	16	2	13	5.4	6.6	0.2	12% C, 6% Potassium
Cranberry	0	0	12	5	4	0.6	3.3	0.1	22% C, 6% E, 6% K, 18% Mn
Date	2	0	75	7	66	32.0	33.7	0.5	8% Niacin, 12% B6, 8% Pantothenic Acid, 6% Ca, 14% Mg, 6% P, 20% Potassium, 18% Cu, 15% Mn
Fig	1	0	19	3	16				6% K, 6% B6, 7% Potassium, 6% Mn
Grapefruit (pink)	1	0	11	2	7	1.8	1.6	3.5	23% A, 52% C
Grape (red or green)	1	0	18	1	15	8.1	7.2	0.2	18% C, 18% K, 5% Potassium, 6% Cu
Guava	3	1	14	5	9				12% A, 381% C, 6% B6 12% Folate, 12% Potassium, 11% Cu, 8% Mn
Kiwi	1	1	15	3	9	4.4	4.1	0.2	155% C, 7% E, 50% K, 6% Folate, 9% Potassium, 6% Cu
Lemon	1	0	9	3	3				88% C
Lime	1	0	11	3	2				48% C
Mango	1	0	17	2	15				15% A, 46% C, 6% E, 7% B6
Melon (honeydew)	1	0	9	1	9	3.0	2.7	2.5	30% C, 7% Potassium
Nectarine	2	0	15	2	11	1.4	1.6	4.9	7% A, 9% C, 6% Niacin, 6% Potassium
Orange	1	0	12	2	9				75% C, 7 Thiamin
Papaya	1	0	10	2	6				22% A, 103% C, 10% Folate, 7% Potassium
Passion fruit	2	1	23	10	11				25% A, 50% C, 8% Riboflavin, 7% Niacin, 9% Fe, 7% Mg, 7% P, 10% Potassium
Peach	1	0	10	1	8	1.5	2.0	4.8	7% A, 11% C
Pear	0	0	15	3	10	6.2	2.8	0.8	7% C, 6% K
Pineapple (sweet)	1	0	13	1	10	2.2	1.7	6.5	94% C, 6% B6, 6% Cu, 41% Mn
Plum	1	0	11	1	10	3.1	5.1	1.6	7% A, 16%, C
Pomegranate	1	0	17	1	17				10% C, 6% K, 6% Pantothenic Acid, 7% Potassium
Raspberry	1	1	12	6	4	2.4	1.9	0.2	44% C, 10% K, 34% Mn
Rhubarb	1	0	5	2	1				13% C, 37% K, 9% Ca, 8% Potassium, 10% Mn
Strawberry	1	0	8	2	5	2.4	2.0	0.5	98% C, 6% Folate, 19% Mn
Tamarind	3	1	63	5	57				6% C, 29% Thiamine, 10% Niacin, 7% Ca, 16% Fe, 23% Mg, 11% P, 18% Potassium
Watermelon	1	0	8	0	6	3.4	1.6	0.1	11% A, 13% C

(All data from nutritiondata.com. Vitamin and mineral content are given as % daily value. 'K' is Vitamin K; potassium is spelled out.)

As you can see, fruits are mostly sugar and water. There's typically about 1% protein, no fat, a modest amount of fiber, and a very small amount of more complex nutritive carbohydrate. Some fruits are admittedly good sources of particular vitamins and minerals, but you get a pretty generous "spoonful of sugar" with your daily dose of vitamins and minerals if you get them mostly from fruit. If you're after the trace nutrients, you'd be better off with vegetable sources anyway. Compare the following (the first three of which are arguably "fruits" in the botanical sense, although we usually call them "vegetables," because of the ways we tend to serve them).

"Vegetable"	Protein	Fat	Carb	Fiber	Sugar	Fructose	Glucose	Sucrose	Other
Tomato	1	0	4	1	3	1.4	1.2	0.0	17% A, 21% C, 10% K, 7% Potassium, 6% Mn
Cucumber	1	0	4	0	2	0.9	0.8	0.0	21% K
Green Bean	2	0	7	3	1				14% A, 27% C, 18% K, 6% Thiamine, 6% Riboflavin, 9% Folate, 6% Fe, 6% Mg, 6% Potassium, 11% Mn
Broccoli	3	0	6	2	2	0.7	0.5	0.1	12% A, 149% C, 127% K, 7% Riboflavin, 9% B6, 16% Folate 6% Pantothenic Acid, 7% P, 9% Potassium, 10% Mn

There doesn't seem to be any good reason to eat fruits for their higher vitamin content; the vegetables have more vitamins anyway! Vegetables provide generous amounts of fiber as well.

So then maybe fruit sugars are somehow better for you? Certainly many "natural foods" advocates seem to believe that "natural" and "unrefined" sweeteners are somehow OK when table sugar is not. But the sugar in most fruits is nutritionally almost the same as that of table sugar. Table sugar is sucrose which is a disaccharide made up of equal parts fructose and glucose. Most fruits also have approximately equal amounts of fructose and glucose either separately or combined as sucrose. The body breaks apart the sucrose right away. Fructose and glucose are metabolized somewhat differently. While fructose has an apparently lower glycemic response, it appears to be more harmful overall resulting in elevated triglyceride levels and fat storage much more than does glucose. So focusing on apples and pears with their higher fructose content is probably even worse than going for the fruits with more balanced sugar content. A more detailed discussion of the metabolism of fructose and glucose can be found in Basciano et al., "Fructose, Insulin Resistance, and Metabolic Dyslipidemia," Nutr. & Metab., 2005, 2:5.

So my conclusion from all this is that fruits are not health food! They're by no means terrible, especially when consumed in moderation as whole fruit, but as macronutrients, they are primarily bags of flavored sugar water. Particularly if you are trying to cut back on total carbohydrate consumption and on sugar consumption in particular, you should seriously consider limiting your fruit intake and increasing your vegetable intake instead, or at least focusing on lower-sugar fruits such as raspberries, blackberries, and cranberries. For us, fruit is relegated to the role of dessert, to be consumed once or twice a day in ~½-cup portions, to alleviate carb cravings. This way, the sugar loading from fruit is kept to a minimum of 20–25 g.