Tuesday 4 February 2014

Should you eat white potatoes?

I was going to make the title “You say potato, I say potato”, but the written word doesn’t really convey that sentence very well now, does it? I’d have to spell it out like they do in the Oxford: “pohtahtoh” and that would just be too confusing.

Secondly, I figured a title asking a provocative question would be more effective at sucking you in. “Oh my god!! Should I eat white potatoes? I must check this out!”

Was I right or was I right? (Lesson number one to get people to agree with you: don’t provide options for disagreement).

Now, we are going to get to the topic of white potatoes, but first I want to leave you hanging just a little to update you on some personal information, most of which you probably couldn’t give a rats-arse about. Whatever, it’s my blog. I can do what I want. (But really, if you have to make an important potato decision in the next few minutes, feel free to scroll down to the promised information).

Update #1 – I’m now living in New Zealand and it’s sweet as, eh bro!?
If you didn’t already know, I married a kiwi a few years back. Kiwi men are pretty great, actually. Especially mine. That’s why I agreed to come back to the mother ship with him. We spent the last month doing a little tiki-tour around the south island (you can see some pics HERE in my last post) to see where we felt comfortable (and where had the best kombucha) and where we might like to settle down. We decided on Wanaka. Here is a gratuitous shot of said place:

Image via lakewanaka.co.nz
Visitors welcome! The ski-fields in the winter are apparently the best in the country. During the summer it's pretty amazing, too. 

Update #2 – I’m writing stuff in other places
Yep! I’m cheating on this blog with a couple of other sites. I’m becoming a blog tart:
a) Woman.com.au – you can check out my first post HERE 
b) I Quit Sugar – I mostly write in the forums, which are only accessed by people completing the program, but occasionally I will offer my “expert” opinion on matters of interest, such as coffee HERE

Check them out and let me know what you think!

Update #3 – I’m writing an ebook
 I realise this could have nestled under “Update #2”, however I wanted to add an extra update to make myself seem more important.

I started writing a little ebook on health and wellness this morning. I’m planning on it not being a monster of a book. More of a get-started primer. If you’re lucky, it may be free, at least for those of you who are good at bribery. More on this as it progresses. Progression may be slow as I tend to get distracted by things like Grey’s Anatomy and trampolines:

Jumping on the trampoline with my 4yr old niece, Lucy
Back to the spuds

Do you ever say things because everyone else says them? Or because they sound right? Or because potatoes taste too good to possibly be good for you? Or because Mr Potato-Head rubbed you up the wrong way? 

Look at him - all smug and potatoey! Image source
A few years ago, I was home in the country with my parents. My mum cooks a pretty mean baked dinner – something I look forward to (and specifically request) each time I go home. This time I shunned the baked white potatoes exclaiming, with mild disgust and an air of arrogance:

“O.M.G! White potatoes are pretty much just piles of sugar. They are nothing else. They are no good for you! (and I am the source of all knowledge because I’m a dietitian!)”

And I proceeded to sit smugly, enjoying my baked dinner sans-white potato (but loaded with sweet potato), knowing (thinking) that my blood sugar levels would thank me later.


My Dad tried to tell me otherwise, stating that he once went on a diet where he ate loads of potatoes every day. He said he felt amazing and that he actually lost weight. “It must have been something else that you were doing. It could not have been the potatoes”, I said. Dismissive little shit, I was.

Where did this “potatoes=sugar=poison” mindset come from?
  1. Paleo diet enthusiasts. Back in the day, all carbs were bad as they cause blood sugar to rise and insulin to release, which is the devil hormone (not really) as it promotes fat storage (among many other important processes), therefore carbs suck. And potatoes are a great source of carbs. Therefore potatoes suck. We now know better. Carbs aren’t so bad (for most people, especially those who exercise and are free of chronic diseases such as diabetes and obesity). More on this in an upcoming post. It was also thought that ‘taters don’t have anything in them BUT carbs. You’ll see evidence to the contrary below
  2. Mainstream dietetics. Yep, this was one of those situations where both camps (paleo vs mainstream dietitians) agreed on something. Potatoes are high on the glycemic index (higher than table sugar, infact), meaning, as mentioned above, they cause a large spike in blood sugar. I don’t really agree with the glycemic index. I wrote about why on I Quit Sugar, which you can read HERE.
  3. Potatoes are white. Sugar is white. Cocaine is white. Uncool by association, I suspect. 

Are the ‘taters really all that bad?

As it turns out, and as you may have guessed already, no. No they are not. Now, it is no secret that I have a bit of an obsession with sweet potatoes. They are delicious morsels of goodness in every way shape and form. But for the sake of this post, I want to compare the nutritional content of the sweet and white potato. Let’s do so by way of an easy-to-view table, previously constructed by yours truly. I’ve even highlighted some points of interest:

Potato vs Sweet Potato per 100g

New (white) potato
Sweet potato
Energy
419kJ
362kJ
Moisture
72.1g
74g
Protein
3.5g
2.3g
Nitrogen
0.56g
0.37g
Fat
0.2g
0.1g
Dietary fibre
2.4g
3.7g
Fructose
0.1g
1.5g
Glucose
0.5g
2.1g
Sucrose
0.3g
3.3g
Maltose
0g
0g
Lactose
0g
0g
Total sugars
0.8g
6.8g
Starch
18.6g
10.4g
Available carbohydrate
19.4g
17.2g
Calcium
7mg
33mg
Iron
0.91mg
0.61mg
Magnesium
30mg
17mg
Potassium
779mg
305mg
Sodium
5mg
12mg
Zinc
0.53mg
0.61mg
Thiamin (B1)
0.116mg
0.031mg
Riboflavin (B2)
0.043mg
0.058mg
Niacin (B3)
1.8mg
1.16mg
Niacin Equivalents
2.62mg
1.86mg
Total folates
15ug
12ug
Dietary folate equivalents
15ug
12ug
Alpha carotene
0ug
55ug
Beta carotene
0ug
7244ug
Cryptoxanthin
0ug
329ug
Beta carotene equivalents
0ug
7436ug
Retinol
0ug
0ug
Retinol equivalents
0ug
1239ug
Vitamin C
29mg
30mg
Tryptophan
42mg
38mg
Source: NUTTAB 2010 Online Searchable Database


OK, let’s go through some of the highlighted points:

  1. White potatoes have slightly more protein than sweet potatoes, although I would not recommend counting on either as a bioavailable (available to the body) source of protein. The best protein comes from animal sources. Sorry vego friends.
  2. Sweet potatoes have more fructose than white potatoes, and the ratio of fructose:glucose is higher in sweet potatoes. Why does this matter? Glucose is easily absorbed into the bloodstream. Fructose, not so much. If paired in equal amounts with glucose, there shouldn’t be a problem – you could view glucose as a bit of a vehicle for fructose. If there is more fructose than glucose, this could spell issues for people with digestive problems, especially those who cannot tolerate FODMAPS.
  3. White potatoes have a considerably higher starch content, which breaks down to glucose to be used for energy or to replace glycogen stores (glucose which is stored in the liver and muscle). Note: this starch content comes in handy when cooked potatoes are cooled for ~24hrs, producing “resistant starch” which, more evidence is proving, has some pretty nifty beneficial effects on the gut flora and digestion.
  4. Sweet potatoes have a higher calcium content. Would you have thought of these little babies as a source of calcium? No? Good. You would have to eat a shite-load to get anywhere near the mainstream recommendations of 1,000mg per day.
  5. White potatoes have around double the content of magnesium and potassium! Going by the NHMRC nutrient reference values, 100g of potato (about 1 large new potato) provides ~27% of your daily requirements for potassium. Fun fact: 100g of banana (about 1 medium) provides ~346mg of potassium. And this: 100mL of coconut water provides ~200mg of potassium. Conclusion: potatoes shit all over these other sources! Just in case you were wondering, potassium is important for blood pressure regulation and heart health, maintaining electrolyte balance within he body, kidney health and more!
  6. Sweet potatoes blow white potatoes out of the water when it comes to beta-carotene, which is a precursor for vitamin A. The daily recommendations for vitamin A, expressed as retinol equivalents is 700ug/day (micrograms/day). A 100g serve of sweet potato provides more than 10 times that amount! Wowsers! Vitamin A helps maintain normal reproduction, vision and immune function. Note that beta-carotene (and other carotenoids) are precursors for vitamin A. Just because there is a tonne of the precursor in the food, this doesn’t mean you are going to be able to convert it all to its usable, vitamin A form. Pre-formed vitamin A is only found in animal products, such as liver, eggs and grass-fed butter, so best you go and make some pate! 

So there you have it! The ‘taters aren’t so shabby after all, are they? I certainly have enjoyed adding them back into my diet. Here’s how I like to munch on them:

Image by Norma Miller via pinterest
  1. Peeled and roasted in duck fat and sea salt until they are crispy. If you haven’t tried potatoes this way, you haven’t lived.
  2. Boiled/steamed and served with a great big dollop of grass-fed butter. Note: boiling will reduce the potassium content by about 50% as it is lost to the surrounding water
  3. Boiled/steamed and mashed with butter and chives, or cumin, or both!
  4. Cooked, cooled and eaten with a smattering of sea salt OR thrown into a potato salad with some homemade mayo. 

 Now go and enjoy some yummy, AND nutritious, potatoes my friends!

Nutrition information sources:

2 comments:

  1. thank you for sharing this interesting article

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  2. I've had great success using my iPad/ iPhone for menu planning. I just created a new event for breakfast ,lunch and dinner and I set reminders to thaw or soak items. I have tried many different ways, including your menu planner, and this one seems to keep me on track the best. I also agree that planning two weeks at a time is a Big time saver. I am working on doing that more regularly. The great thing about having it on my phone is if I am at the store for a quick trip, I can look at my phone and see my menu, to make sure I didn't leave something out. It's also nice to look back over the last few months to get ideas for the upcoming week.
    Thanks so much for your site! I love your ideas and recipes.

    . Nutrition

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