As a nutritionist, one of the questions I get asked often is:
Will eating fruits make me fat?
Is it true? Not at all. There’s no scientific evidence that shows that fruits cause weight gain, yet so many health bloggers and diet “gurus” ask people to ban or limit fruit.
What’s going on? Why does fruit have such a bad rap these days and what does the science really say about fruits?
Why do fruits get a bad rap?
In the past decade, many diet books and blogs have banned or shunned fruit.
Two main (faulty!) reasons are:
1. Fruits are high in carbohydrates and eating carbohydrates is thought to lead to weight gain.
In the late 2000s, Gary Taubes promoted a theory for obesity in his book Good Calories, Bad Calories. This theory, known as the carbohydrate-insulin hypothesis of obesity, says that carbohydrate is the main cause of obesity due to its ability to increase insulin levels. These increased insulin levels result in increase fat storage in the body, so we become “fat”.
The theory is just a theory, it hasn’t been conclusively proven in any scientific papers I’ve seen. In fact, there is one new study  that disproves the theory that carbs make you fat. You can read a thorough analysis here.
Also, it’s important to note that there is a difference between eating processed carbs like cookies, cakes, fries, etc. and eating carbs from healthy foods such as fruits and vegetables.
Processed and refined carbs or “junk” carbs are easier to overeat (so you end up eating more carbs than your body can handle) and they also impact your metabolism differently from carbs in healthy foods like fruit and vegetables [2, 3, 4, 5].
Just because fruit contains “carbs”, we can’t assume it will impact our weight the same way as a cookie binge.
Carbs don’t make you fat – excess carbs and refined carbs do. Fruit in reasonable amounts isn’t a problem 🙂 .
2. Fruits contain fructose. Fructose is thought to cause inflammation and is considered a driver for obesity.
Fructose has been called a “poison” and a “toxin” by health professionals such as Dr. Lustig. Is it really that bad? The answer is not that simple.
Sounds worrisome right?
It is, but the one thing to note is that these studies usually talk about fructose in the form of high fructose corn syrup (HFCS).
HFCS is vastly different from the fruit even though they both contain fructose. Can we conclusively say that fructose from fruit has the same negative effects as high fructose corn syrup? I don’t think so.
First of all, fruit doesn’t contain as much fructose as processed drinks that contain HFCS. For example, one medium banana has 6 g of fructose . A one 20 oz. bottle of cola contains 65 g of HFCS  out of which 35+ g are fructose.
You would need to eat 6+ bananas to get the same amount of fructose as a bottle of cola. Would you do that on a regular basis? Probably not!
Also, fruit has fiber and vitamins, minerals and phytochemicals that are good for us, so to assume that it impacts our bodies the same way as HFCS does not make sense. Especially since there is no evidence to support that. In fact, some studies say that recommendations to cut down on fructose do not apply to fructose found fruit and vegetables .
And you know what? The biggest critic of fructose, Dr. Lustig, actually recommends his readers eat whole, unprocessed fruit as part of a balanced diet . It’s the processed stuff he has a problem with.
Is there any science that shows that fruits aren’t associated with weight gain?
Yes! Here are a few studies that show that instead of weight gain, whole fruits (not fruit juices) are associated with a healthy weight.
- One study that followed 18,000+ women showed that a higher intake of fruit was associated with a lower risk of obesity .
- A scientific review published in 2009 looked at sixteen studies to see the relationship between fruits and body weight. Majority of the evidence in this review suggested that fruit consumption does not cause weight gain. In fact, it is linked to lower risk of obesity .
So it seems like eating fruits is associated with LOWER body weight.
It’s safe to say fruits probably aren’t going to make you fat .
How much fruit can you eat?
Everyone is a bit different, so what works for one person may not work for another.
As long as you are a healthy individual who does not react negatively to fruit (i.e. no digestive issues or metabolic issues), then 1-4 servings of fruit seems to be reasonable. Note: If you’re more active, you can eat towards the higher end of the range.
Go on an enjoy some fruit! Life is too short to be deprived of nature’s bounty ;).
What should you keep in mind re: your fruit consumption?
- Eat whole, unprocessed fruits – not fruit juice. Fruit juice does not have much fiber, so it is not as satiating and it’s easy to overdo it. In fact, fruit juice is linked to obesity [20, 21] although there are also studies proving the opposite. It’s hard to say conclusively whether or not fruit juice is a good choice. If you do choose fruit juice, make sure it’s not the processed kind. Fresh is best and in moderation. Better yet, mix in some of the pulp!
- Limit dried fruit. Dried fruit is another thing that is very easy to overdo.
- If you have pre-diabetes, diabetes, metabolic syndrome or high triglycerides, speak to your healthcare professional about what types of fruits are better for you and how much. Each person is different, so your requirements may vary. In general if you have blood sugar issues/metabolic issues, it’s best to limit fructose, so choose low fructose fruits like berries and kiwis.
- If you have digestive issues (leaky gut), fructose malabsorption or a digestive disorder, you may need to limit your fruit until your issues have resolved. It’s best that you speak to a naturopathic or integrative doctor regarding that.
- If you’re trying to lose weight, don’t limit your fruit, but don’t go crazy with it either. Excess calories from any food can cause weight gain. Eat a reasonable amount (1-3 servings) and you’re good.
P.S. You might be thinking – what’s a serving of fruit? Here’s a good resource with information on what counts as a serving.
Hope you found this post useful. If you have any questions or comments, would love to hear from you. Leave us a comment below (scroll past the section called “other posts you might like”).