With many people currently on the quest for a leaner physique, a question that repeatedly arises when people choose to restrict their carbohydrate intake is "are fruits fattening and should I avoid fruit if I am trying to cut body fat?"
First of all, "fattening" is a word I don't like. Foods certainly vary in energy and macronutrient content, and some should not be eaten in large quantities all the time, but that doesn't make them inherently "fattening".
I am thinking of natural, whole foods in this case – obviously you know my stance by now on processed foods. All fresh, whole natural foods can fit into a varied, balanced diet as long as you are doing appropriate physical activity.
If people only ate whole, unprocessed foods like lean meats and fish, fruits, vegetables and nuts, and were physically active, I believe we wouldn't have an obesity epidemic.
Fruit contains vitamins, minerals, fibre, antioxidants such as vitamins C and E, carotenoids, flavonoids and polyphenols which may protect against free radicals. If fruits are so rich in goodness, then why do some people suggest you should avoid them?
WHAT ABOUT THE SUGAR IN FRUIT?
The claim fruit is "fattening" seems wholly centred on the fact that fruit contains a natural sugar (fructose).
There is accumulating evidence that consuming fructose in excess can lead to increased risk of diseases such as obesity, diabetes and the metabolic syndrome. However this, by and large, pertains to studies in rodents with sweeteners and a processed form of sugar derived from corn starch named high fructose corn syrup (HFCS) – that's very different to a human consuming whole fruits containing fructose.
When fruit is digested, and the fructose is released, it is taken up by the liver and used preferentially to replenish liver glycogen (a storage form of carbohydrate in the body). In animal models, high fructose intakes cause damage to the liver resulting in a range of metabolic derangements. However, fructose consumption from fruit does not result in the same negative metabolic effects compared with over-consuming sugary foods or HFCS. How so?
Fruit contains a lot of water by weight, and is generally rich in fibre, so this also helps to slow the release of energy. The liver can process and store roughly 50g of fructose daily without any adverse effects such as those seen in the rodent studies. Eating fruit, which contains roughly 10g of fructose per portion, is unlikely to result in any negative consequences.
On the other hand, you could easily consume 50g of fructose if you drank a lot of processed fruit juice, fizzy drinks or ate food or drinks sweetened with HFCS.
This is why looking at your diet as a whole is so important and explains why fruit intake itself is unlikely to be your downfall – unless, of course, you are overdosing on smoothies.
WHY DO SOME PEOPLE CUT OUT FRUIT?
There are certain foods that can fit an individual health goal better than others. For example, if you are aiming to reduce body fat by using a low-carbohydrate diet, there are certain fruits that can fit your dietary approach better than others.
Certain fruits are higher in carbohydrate than others and we try to compare them on a portion-size basis.
Grapes, mango, pineapple, bananas, pears, melon and papaya are examples of "high" carbohydrate fruits, which makes them ideal for athletes or anyone who requires a significant amount of carbohydrate in their diet.
In terms of portion size, one medium-sized pear or banana contains 27g of carbohydrate, whereas a half-cup of blueberries or raspberries contains 10g. If you were aiming to develop a leaner physique, a simple approach is to consume higher carbohydrate fruits around your training.