Nutrition Questions


From Ilse; here’s a question. I love smoothies, fruit smoothies as well as so called green smoothies, it helps me to get to my greens and fruits in an easy way. My question: do the veggies and fruits I put in my smoothie lose nutritional value because of the immense powers and friction they are subjected to in the blender? And what about the real juicers? I tried to find an answer on the internet, but the answers I find there have been contradicting so far. Would love to hear your view on this.
Hi Ilse, during my study we haven’t spoken much about juicing or blending (smoothies) from fruit and or vegetables, but there are a few things I can think of.
  • For example: vitamin C is a vitamin that breaks down upon oxygen exposure, like the browning of apples when they get bruised or cut. Keeping that in mind it is probably smart to consume your smoothie right after you made it.Secondly; vitamin C is one of those vitamins our body can’t store, so you will need some daily. Grown women need about 75 mg a day (if they don’t smoke), some good sources: orange, papaya, kiwi, pineapple, but also broccoli, bell peppers and spinach
  • Thinking about the technique that is being used: a smoothie blends the fruits and or vegetables, has a fairly thick texture and includes all parts you put in the blender. With a juicer fiber stays behind and you drink a more liquid like drink. As you might have read from my blogs, fiber is very important. 1) for our digestive system 2) for our cholesterol levels,because some fibers; for example fibers from oats, apple and citrus help keep cholesterol down in our blood, 3) blood sugar levels spike more slowly and less when we receive fiber and 4) fibers help us to feel full quicker. think about orange juice; a glass full of orange juice might be coming from 4 oranges depending on how much is in your glass.. are you able to eat 4 oranges at one time? You probably feel full for a while, longer than with juice.
  • I do agree it is an easy way to get your greens and fruits. For that reason I would say; just save it for those occasional days when you know you come short and just keep blending; it will give you a chance to take advantage of the fiber

Nancy: what’s your take on Vit D supplementation?

Hi Nancy: my take is that if you are healthy: get vitamin D from food and sun first (be careful not to sun burn though), but clothing, sunscreen and season can have an effect on intake. Much research is done and is still going on. There are still unanswered questions, like; can vitamin D help against cancer, does it help against osteoporosis, etc. A helpful article:


From Ilse: I would love to know if there are any negative physical side effects of drinking coffee first thing in the morning. Is it better for the body to start with something else, like tea or fruit juice? I hear different things about this and am just wondering. I love my coffee in the morning šŸ™‚

Hi Ilse, coffee is a complex drink with many different compounds so it makes sense that you hear different things. If you are somebody who is prone to heartburn; when acidic juices from your stomach come back up easily in your esophagus (throat) than coffee might not be the best choice for you. But in that case so would be juice or tea, because all these drinks are acidic and those can make heartburn worse.

With the help of research more and more benefits are found to drinking coffee. Coffee has been linked to lower chances of type 2 diabetes, less depression for women and to lower chance of prostate cancer for men. I think Harvard has done a nice job putting all those studies in one article. I will add the link here in case you are interested. One disclaimer though: In those studies we are talking about the black stuff, not the coffees that many people like to drink from coffee shops with added whole milk and large amounts of sugar. These might be detrimental to your health if the added calories are being stored by your body instead of burned, or when these coffees are taking the place of healthy meals. I hope this answers your question!

Ilse:Thank you! Question answered . Funny how theories have changed, but I like the outcome haha!

from Melinda: Gluten Free…is it for everyone? Margreet says: See my blog post from Dec 2012

from Ingrid: I hope I can find the courage to cut my sugar consumption the next weeks! If you can give me some encouraging words, I can use them! Margreet says: A great idea Ingrid! With the Holidays and the cold upon us, many people are in the mood for something sweet. A running coach and friend of mine encourages his students to make sure that 90% of the foods they eat are healthy. If you know you can stop after 1 or 2 sweets that is something you can try. But if you are somebody who can’t stop once you start, better focus on something healthy you can eat or serve during the coming weeks. I am adding a recipe to this post and I will add more in the coming weeks. Stay tuned

from Isabella: How much protein should I eat as a teenager/athlete if I play a sport 5 out of 7 days? Margreet says: Good question! As a growing teenager that exercises a lot you need about the same or a little more protein than most of your classmates. If you want to do the math: 0.7 to 0.9 grams x your body weight in kilograms. In the attached article you will find an overview of how much protein can be found in for example milk, beans, eggs, meat, etc and you can add up what you eat during the day. You will probably find out that you will do just fine, or that you go over. Try it out for a day. Make sure you also eat enough carbohydrates (fruits, vegetables, grains) since carbs are your first fuel source as an athlete. Consuming enough carbs will make it easier to run fast and for a longer period of time. I hope this answers your question…

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