Category: Ask Monica

Your nutrition questions answered

Does Caffeine Increase Fat-Burning During Exercise?

by Monica Reinagel, MS, LDN

Q. I read recently that the consumption of caffeine prior to exercise will assist the body in using body fat as fuel, up from 21% to 40%. The remaining fuel comes from stored carbs. Any truth to the story?

A. There may be a grain of truth to the story but not much more.  Taking caffeine  before exercise has been shown to increase energy expenditure (the number of calories burned) during exercise by around 10%.  So if you would normally burn 200 calories in a half-hour, some extra caffeine might help you burn 220.  Continue reading “Does Caffeine Increase Fat-Burning During Exercise?” >

What are Nightshades and Why Do People Avoid Them?

by Monica Reinagel, MS, LDN

Q. What’s the deal with nightshades? Why are they supposedly bad? I love eggplants and tomatoes but wonder if I should limit my consumption of this group of foods.

A.  Here’s the deal: Tomatoes, peppers, and eggplant (as well as potatoes and tobacco) all contain an alkaloid called solanine.  The Latin name for this family of plants is Solanaceae, but they are more commonly known as the “nightshades.”

People with arthritis are often advised to avoid nightshade plants because they supposedly aggravate joint pain. But nightshade plants aren’t a problem for everyone, just a small number of people who have a particular sensitivity to solanine.  It’s a little bit like an allergy…some have a noticeable reaction while others have no reaction at all.

Continue reading “What are Nightshades and Why Do People Avoid Them?” >

What’s the Deal with Ultra-Pasteurized Milk?

by Monica Reinagel, MS, LDN

Q. I would like to hear more about ultra-pasteurization of milk. I have noticed that organic milk does not spoil as fast as non-organic milk. Is it the ultra-pasteurization? And why is organic milk ultra-pasteurized while regular milk is not?

A. Ultra-pasteurization, which heats milk to 260 degrees F. as opposed to the 160 degrees F. required for regular pasteurization, triples the shelf life of milk. Most big-brand organic milk is now ultra-pasteurized, so that’s probably why you’ve noticed that it doesn’t spoil as quickly as normal milk.

As to why the ultra-pasteurization process has been widely adopted by the organic market and not the conventional milk market, I can only speculate. Continue reading “What’s the Deal with Ultra-Pasteurized Milk?” >

Dessert Rules

by Monica Reinagel, MS, LDN

Q. I am a healthy, active person trying to maintain my weight. About once or twice a week I will have a nice dessert at my favorite bakery, staying within my allotted calories for the day. My question is: though I’m keeping calories down, is it still healthy?

A. Well, sweets aren’t exactly health-promoting.  Nonetheless, But I do believe that a healthy diet can include the occasional sweet treat. Here are my guidelines:

Continue reading “Dessert Rules” >

Is Coconut Sugar a Healthier Choice?

by Monica Reinagel, MS, LDN

Q. Makers of coconut sugar claim that it has a low glycemic index and is high in potassium and some other minerals.  Would using coconut sugar make my cookies the healthiest on the block?

A. Replacing cane sugar with coconut sugar might make your cookies a little higher in potassium.  And to the extent that coconut sugar has a lower glycemic index than regular sugar, the cookies might not cause quite as high a bump in blood sugar–although I’m sure it would still be significant.

But here’s the thing: The fact that coconut sugar has a lower glycemic index is a tip-off that it has a high fructose ratio.  (Same is true of agave nectar.)  There’s been a lot of buzz about fructose lately: how fructose doesn’t stimulate the release of hormones that signal satiety or fullness, leading to over-consumption and how over-consumption of fructose triggers fat storage or even liver damage.  Most of the hysteria, of course, has been focused on high fructose corn syrup. Ironically, high fructose corn syrup is a lot lower in fructose than “healthy” sweeteners like coconut sugar and agave nectar. Continue reading “Is Coconut Sugar a Healthier Choice?” >

Does Cooking With Oil Create Trans Fats?

by Monica Reinagel, MS, LDN

Note: This post was updated on 11/24/2013 to correct a typo in the temperatures required to isomerize fats.

Q. How exactly is trans fat created? If I bake with some (say, 1/4 cup) oil in a batter, does that make trans fats?

A. We’ve all read a lot about the dangers of trans fats.  Most of the trans fat in our diet comes from artificially hydrogenated oils that are still widely used in food manufacturing. These “Franken-fats” are polyunsaturated fatty acids (PUFAs) that have been twisted into an unnatural configuration called a trans-isomer. This means that the molecule contains the exact same number and type of atoms as it did before, but they are arranged in a different shape.

But what a difference that small change makes!  Polyunsaturated fats and their trans-isomers produce completely opposite effects in the body. While PUFAs help to improve cholesterol profiles and reduce your risk of heart disease, trans fats contribute to heart disease by fueling inflammation, raising bad cholesterol and lowering good cholesterol. Continue reading “Does Cooking With Oil Create Trans Fats?” >