Heating Blueberries

OP, don't drive yourself too crazy with this. Blueberries that were harvested a couple days earlier than others will have less calories than the later harvest, ones that grew in even slightly higher temperature environments will also be slightly higher... unless you know the absolute minutiae of the temperature at which the berries grew through the whole process, the extra cals from microwaving won't make a bit of difference, and really wouldn't be accurate in any event, as there is up to a 20% margin of error in any recorded calorie count.

I also find this interesting-thanks OP. However, I agree that the change in calories is minimal and won't sabotage your weight loss. Good on you for wanting to be accurate--we need more people like you.

Izzwoz wrote: »

So heating blueberries adds calories? How? Does the microwave add sugar? I think it might just be a matter of "concentrating" the calories rather than adding any. Experiment A: So if you take 100 gr of raw berries, microwave them and weigh them again - do they now weigh less? Do they contain the same amount of sugar? Does sugar evaporate? Is life too short? Weigh your berries, log them, eat them - any which way you like. :-)

That's what I'm wondering. Is it dehydration altering the weight or does the heating change the structure or chemical composition.

Alatariel75 wrote: »

yarwell wrote: »

0.001 calories per gram per degree C of extra temperature is the number of calories to add for heating, approximately.

100g of blueberries at 40 C compared to 20C = 2 extra calories.

What counts as "extra" temperature? Like, what's the baseline on which one would expect the USDA calorie count for blueberries was calculated?

Above room temperature or whatever base temperature USDA use.

I don't know the convention in nutrition, but in Thermodynamics generally either 0 or 25 C tend to be common.
"Atwater and Rosa (63) defined the Calorie at 20°C and noted that it was slightly larger than the 18°C unit employed by Armsby (64)." according to http://jn.nutrition.org/content/136/12/2957.full

How on earth can simply heating something up add calories? Where do they come from? Do the blueberries absorb microwave energy somehow and turn it into calories? Interesting. Does this apply to all food? Because I use my microwave a lot.

Do frozen blueberries have less calories? Just kidding, I am not worried about blueberries. It's the chocolate and cake that makes me fat
So if someone is worried that heated blueberries have more calories and wants to calculate each and last of these calories... is it the same like me when I feel cheated when I eat corn?
I mean, I record 100 g of corn but still see a large amount of undigested corn later on at the other end of the digestive process. Should I subtracts those kernels from the overall weight? It's just fair I think

Just to be accurate

So if I have 10 grams of carbohydrates in the form of raw blueberries (40 calories) and I heat them from 20C to 30C (10 grams x .001 x 10C = 1 calorie), you're saying I now have 11 calories in my food.
Do I now have 10.25 grams of carbohydrates (the heat magically created another quarter gram of carbs) or are you saying that hot carbs have more calories than cold carbs?

Also, do I have to eat them while their still hot to get the extra calories? Do the extra calories go away when the food cools back off or do they stay? What if I eat 110F blueberries but my stomach acid cools them back down to 98.6F before they have a chance to digest? What if I eat 70F blueberries but my stomach acid warms them to 98.6F?

Should I only eat cold soup when cutting because the hot soup has more calories?

Do we need "hot" and "cold" entries in MFP?

If heating adds calories, does freezing reduce them? Can I get ice cream cold enough to make it virtually calorie free?

What if "because Yarwell said so" isn't sufficient evidence for the validity of a silly claim that a microwave can add calories to your food?

auddii wrote: »

How do you account for blowing on your food? And do we need to be taking the temperature of each bite before consuming? What about the loss in temperature while the chewing process occurs? Isn't all food body temperature by the time it reaches the digestive tract?

FOR THE LOVE OF GOD, HOW ARE WE SUPPOSED TO CALCULATE CALORIES NOW?!

Need a food scale AND a thermometer.

Or eat everything at room temperature, including popsicles.

OP it's great that you want to be as accurate as possible, but there are MANY factors at play when measuring the CICO equation and when it comes down to it, all of them are really just estimates. The best you can do is try to be accurate in big ways (logging everything you eat, using a food scale, having a realistic understanding that exercise burns may be overinflated and adjust accordingly) and not sweat the minute details like if heating your blueberries in the microwave adds 1 calorie to them. Or, while they are hearing, walk one lap around your kitchen and it's a wash.

Focus on the big stuff. Don't major in the minors. Consistency is what really matters.

Good luck.