When fruit makes you FAT





It is amazing that in today’s day and age many weight loss “experts” still subscribe to the notion that a “calories is a calorie”.


This is simply not true and today we are going to examine how this relates to fruit.


Back in the late 1990′s I was heavily into bodybuilding. Now, say what you want about the “sport” but let me tell you that when it comes to losing body fat whilst retaining muscle bodybuilders are simply the best.


Bodybuilders take the information nutritionists and dieticians prescribe to a whole other level. In fact, the best body transformation coaches I have ever met were all bodybuilders at some point in their careers.


One of the first foods to scrutinize on a competition bodybuilder’s diet is fruit. Yes, fruit does contain many healthy vitamins but it also contains something that is not so good depending upon whether you are trying to lose fat or build muscle- fructose.


Fructose is unique and different from regular glucose. According to Dr. Lustig, a Professor of Clinical Pediatrics in the Division of Endocrinology at UC San Francisco, fructose is iso-caloric but not iso-metabolic. This means that consuming 100 calories of fructose has a different metabolic effect from eating 100 calories of glucose.


Once eaten, glucose goes directly into the bloodstream. Fructose, on the other hand, must first be transported to the liver where one of three things can happen- it can be converted to glucose, stored as glycogen or converted and stored as fat. Your liver can convert both glucose and fructose to fat however the conversion to fat from fructose is much more efficient due to the bypassing of a liver enzyme called phosphofructokinase or PFK.


This does not mean that eating a few strawberries will cause your fat cells to burst at the seams- fructose will only undergo this conversion to fat under certain conditions;


1. In order for your body to convert fructose to fat you must be in a calorie surplus. This means that if you are a person who is eating above their calorie threshold and has not depleted their glycogen through diet and exercise, the efficiency by which your body converts fructose to fat is greatly enhanced. As I write this I am thinking of how many times I have witnessed over fat individuals gorge themselves on melons, mangos and peaches thinking that they were doing something “healthy”…


2.  If you are a person who exercises regularly and follows a moderate to low carbohydrate diet your glycogen levels are likely low and eating fruit will have no ill effects. The fructose will be converted to glucose and glycogen and used by the body rather than being stored as fat.



Should YOU be eating fruit?

The answer to this question may sound familiar- it depends. If you are a person looking to lose body fat then you need to be eating fewer carbohydrates, eating in a calorie deficit and exercising your whole body 3 times per week. This will result in a depletion of liver glycogen and as such eating a small amount of fruit will not be a detriment to your fat loss efforts. I always recommend that my clients eat mainly small dark berries as these have the highest nutrient density and lowest amount of fructose.


On the other hand, if you are a person whose goal is to gain muscular body weight you need to be eating more calories and carbohydrates and are likely to have sufficient amounts of liver glycogen. In this instance eating fructose may result in greater fat accumulation despite your hard training efforts. This will require that you keep an eye on your nutrition labels as many weight gain products are sweetened with fructose or Agave (which is 90 percent fructose).


Regardless of your goal I always recommend keeping fructose levels relatively low (about 30 grams or less- the equivalent of approximately 3 apples).  This should come from whole fruits only and not from processed foods or high fructose corn syrup.


All fruits are not created equal

All fruits contain fructose but some more than others. Fruits such as lemons, limes, tomatoes, coconuts, grapefruits and avocados are the lowest while prunes, figs, raisins and mangos are among the highest. Honey also has a relatively high fructose content.

For a more complete listing of fructose content in foods you can check out this website: http://nutritiondata.self.com/foods-000011000000000000000.html


From a body composition standpoint the answer to whether or not you should be eating fruit is dependent upon what you are trying to achieve. If you are in a fat loss phase then have some fruit but do so in small amounts and stick with those fruits that pack the biggest nutrition punch (small, dark berries for example). If you are in a weight gain phase then leave the fruit alone or better still, cycle your calories and have some fruit on your low calorie days. This is the strategy I use year round- I have some fruit on my low calorie days and stick to other carbohydrate sources on my higher calorie days. This type of calorie cycling works well for me and has helped me to maintain a very low body fat percentage without feeling deprived. I find that I can give up just about any food for a short period of time. This is the strategy I recommend and I am confident that it will work for you too.


This post was written by

Bruce – who has written posts on Cutting edge muscle building and fat loss secrets.
bruce krahn is a best-selling author, writer, researcher, personal trainer and professional speaker. he has coached people for two decades both in person and online. he created this site to be an honest source of useful, practical information you can use to improve your health, build muscle, lose fat and get the lean body look.

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bruce krahn is a best-selling author, writer, researcher, personal trainer and professional speaker. he has coached people for two decades both in person and online. he created this site to be an honest source of useful, practical information you can use to improve your health, build muscle, lose fat and get the lean body look.

13 Responses to “When fruit makes you FAT”

  1. Robin says:

    Your articles are always interesting and educational; thank you! I thought that I shouldn’t eat fruit after 3 p.m. but now I see that that isn’t what’s really important. However, I will stay away from the fruit cake this holiday season…. =D

  2. Eileen says:

    Interesting and informative. Fruit, like everything else, has to be consumed in moderation.

  3. Nancy says:

    Tried, tested and true! Great article Bruce.

  4. Russlyn says:

    What about bananas,watermelon,grapes and kiwi are these bad fruits?

    • admin says:

      Hi Russlyn- great to hear from you. No fruits are “bad”. Its just that there are some instances when it is better to consume them. If you are training consistently and keeping carbs relatively low eating small amounts of any fruits is fine. For example, I will often put berries in my post workout drink. However, if you are not training and are eating a moderate to high carb diet you may want to be careful about your fruit intake for reasons explained in the post.

  5. Max Carrara says:

    A great thanks to you for enlightening me about fruit intake on a diet. I’m always skeptical when it comes to eating fruits since we all know they are chock-full of sugar (though natural ones). Not anymore. :)

  6. kat says:

    I would be very happy to hear what you think of low fat high carb fruitarians who, if done correctly show impressive results in terms of fitness and body fat loss (and skin and mood etc). They usually say its important to eat very high calorie, like above 2500 for a women and that this helped them to lean out….with bananas, dates, melons, no fat, no meat, just fruits and some greens.
    its an interesting thing since i thought this could only be achieved with low carb and they just do the opposite
    maybe insulin is only a problem if you eat fat also, but then again i always thought insulin by itself hinders the release of fatty acids.
    do you have an idea?

    • admin says:

      This would only work if they are in a calorie deficit. When it comes to weight loss, this is what matters most. However, you wont achieve an optimal body composition or performance using this approach. You can cause an obese person to lose weight using any diet (even junk food) so long as they are eating fewer calories than they are burning. However, when it comes to getting into peak shape or performance or losing those hard to lose spots you have to pay attention to the finer details.

  7. As the name suggests, natural bodybuilding is naturally to build one’s body. If you only lift ten pounds routinely, your muscles will grow to meet that need and no more. Not only can an elliptical build muscle, but it will also help you burn calories and fat.

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