Tag Archive: nutrition

Is green tea really as great as everyone makes it out to be?

Green tea is toted to be a miracle food by pretty much the entire fitness community. You don’t have to go far to find someone claiming it cures cancer, helps you to lose weight, prolongs your life or a slew of other facts. Are these supported by science or just a bunch of teaholics?

The polyphenols found in tea have shown to delay onset and/or lessen severity in men with prostate cancer.

A recent (June 15th 2012) review of a shit ton of studies found that drinking 10 cups of it a day can delay cancer onset, as well as be part of tertiary cancer treatment

It can improve symptoms of menopausal overactive bladder 

Rats fed a high fat diet and green tea had lower transcription of obesity related genes, as well as inflammation, etc. than just the rat fed high fat diets

Green tea’s antioxidant capabilities can help fight oxidative stress caused by neutrophils in cancer patients

It’s shown to decrease the rate of muscle loss in rats with muscular dystrophy

It can help control sodium balance in people who’ve had an ovarioectomy

No, it doesn’t cause low birth weight in babies, that’s a myth

No, it doesn’t effect drug metabolism

There’s no evidence that green tea pills can cause a serious loss of weight (read: no pill is going to magically make you shed 50 pounds) but it can be used in conjunction with a healthy lifestyle

So it’s true – a lot of the claims about the health benefits of green tea are there. Make sure you read the caveats though: green tea alone won’t cure cancer, make you lose weight, destroy your allergy symptoms, etc. But the health benefits of green tea have been shown in countless studies over a broad spectrum. Some of these studies would be the equivalent of drinking 10 cups of tea a day to get the benefits shown. Like everything, when used in conjunction with a healthy diet and lifestyle green tea can be an amazing addition to your diet.

What is the Paleo diet?

The Paleolithic (Paleo) diet has received a lot of attention lately, mostly due to its popularity amongst certain fitness circles such as Crossfit. Here’s a basic breakdown of what Paleo is and is not.

What can you eat?

The Paleo Diet is a lot like it sounds – they advocate for eating food that a caveman during the Paleolithic diet would eat. This means mostly eating meats, vegetables, fruits, roots and nuts. The Paleo diet excludes dairy, grains, legumes, salt, added sugar and processed oils.

Why?

The rationale behind the diet is based on the idea that the genetic makeup of man has changed very little since the Paleolithic era. Common man, they argue, has modern day ailments (such as diabetes, obesity, etc.) due to introduction of certain foods that are not “meant” to be eaten. By eliminating these foods and looking toward our ancestors and how they ate we can live a healthier life.

Variations

Some Paleo proponents swear off certain foods, such as fruits, or make their diets to be low carb. Like all diets there are variations within the community, and saying “Paleo” does not necessarily mean one eats fruit or one eats low carb. The basic guidelines of no grains, legumes, dairy, added sugar, salt and processed oils is universal.

A case for Paleo

By focusing on meats, vegetables, nuts, roots and fruit one can lead a virtually unprocessed diet. The Paleo movement does fit closely with the “Clean Eating” and “Whole Foods” movement that encourages people to get many nutrients from whole, unprocessed foods. Additionally, people with certain illnesses such as celiacs or dairy intolerance can easily adhere to these diets.

Some great resources for Paleo information:

The Paleo Diet

Everyday Paleo

The case against Paleo

The main drive for the case against Paleo comes from the idea that the basis of Paleo is flawed. That is, a misunderstanding of genetics has lead to false assumptions. While modern man’s DNA doesn’t differ greatly from Paleolithic man, genetics is more complicated. There is no 1:1 ratio between genotype and phenotype. Traits are not simply dominant or recessive, and complex interactions between DNA can cause vastly different expressions phenotypically.

Further, the Paleo movement implies that 10,000 years is not enough time for genetic adaption to diet or lifestyle. We know this to be false because research has shown that Europeans increased their lactose tolerance (genetically) within 1,000 years of the introduction of animal husbandry. Additionally, new research has shown that salivary amylase (which breaks down starch) has increased in modern man.

From an anthropologic stand point Paleo is flawed in assuming that all people in the Paleolithic area ate the same food, regardless of location. The Gwi of Africa had a diet consisting of 23% animal product vs. Alaskan tribes bordering around 99% animal product – all in the same period. Additionally, the introduction of fishing occurred around the Upper Paleolithic era.

Lastly, Wolfgang Kopp stated in a 2006 issue of Preventative Medicine that Paleo also ignores much of the argument of “Natural Selection.” That is, evolution favors those who live to reproductive age. Since Paleo advocates for higher protein, such disease factors as cardiovascular disease will be higher. These disease states occur later in life after reproduction has occurred. He calls this a “functional diet (keeps us alive) that is dysfunctional (causes disease).”

Some articles that warn against Paleo:

The Paleo Manifesto: A Case Against the Hunter-Gatherer Diet

Don’t Eat Like a Caveman by FoodSafetyNews

Take Home Message

Like all diets there are pros and cons. Finding what style of eating works best for you is important. Likewise, everyone should be made aware of the risks of assuming certain dietary choices. There is no one right way to eat, no one food that should be vilified, and no one diet to cure all ills.

When losing weight, what food groups should you avoid?

I get this question a fair amount, so I thought I’d do a lovely post on what foods one should ABSOLUTELY avoid when trying to lose weight. I’m talking about the type of food that can single handedly sabotage your diet, make you pack on the pounds and set back all the progress you’ve made.

Ready for it?

They don’t exist.

There is no one food (peaches, candies, steak, cake) or one type of food (alcohol, dairy, meat) that will cause any sort of setback in your diet.

Why? Because food is not the enemy. Treating food items or food groups as horrible fiends that trick you into craving them with their addictive additives and their easy accessibility gives them way too much power. It’s an item, composed of macro and micro nutrients, with assorted tastes, flavors and sensations. That’s all. Some are enjoyable, some aren’t.

Furthermore, eating fruit or not eating fruit isn’t going to make or break your diet. Weight loss, specifically fat loss, comes down to energy balance. If you put yourself into a deficit (either by diet or by exercise) you will lose fat. If you put yourself into a surplus (either by diet or lack of exercise/activity) you will gain fat (and/or muscle, depending). That’s it. If a food has 200 calories it has 200 calories. Done. There’s no further discussion from a weight loss point. (Before I get 1,000 asks talking about how 200 calories of veggies and 200 calories of cake are not the same, save it. For weight loss they are, for health they’re not. Go away. You’re annoying and redundant and clearly can’t read.)

Let’s set up a scenario. Say that your TDEE (the amount of calories you burn a day as an active human being) is 2,100. Maybe you’re trying to lose weight, so you put yourself at a 300 calorie deficit every day and eat 1,800 calories a day. Awesome. It’s about 5pm and you’ve had your meals for the day but there’s something extra you’re craving – like a piece of cake. You’ve got about 350 calories left for the day and your mom just brought home a delicious cake – Cheesecake. Your favorite. Turns out the calories for the entire piece add up to 400 calories and she wants to split it right down the middle.

But cake! That’s bad food! It’s always listed on that “DO NOT EAT” diet sheet! Guess what – you’ve got plenty of room to eat that cake. And you know what? It’s your favorite. You’ve worked hard. You have the space for it in your meal plan. You’re still hungry and you WANT this cake.

So eat it. Those 200 calories you just ate of cheesecake isn’t going to suddenly morph into 800 calories in your stomach, then grow to 3,500 calories in your intestines and set back all that great progress!

Say you don’t have any extra calories left for the day but you want the cake and you eat it. You’ve eaten 2,000 calories that day. 2,100 calories will keep your weight. 3,500 calories + 2,100 calories will make you gain a pound.

Take this same advice with any food. No, adding milk to your cereal isn’t going to make you gain weight. Adding milk to every item you eat all day, causing you to go over your calorie limit, will. See how that works?

Instead of obsessing over “good food” and “bad food” focus on how food makes you feel. If you really love a type of food, find a way to incorporate it into your diet in a healthy way. Find recipes that make a smaller serving size so you aren’t plagued with an entire cheesecake going bad in your house. Split desserts with your friends, get rid of the “bad food/good food” dilemma. Food is food.

What you shouldn’t focus on is the food, but the feeling. Do you find that chicken makes you feel full longer without putting you into a food coma? Does too much dairy make you gassy and uncomfortable? Do certain carbs make you retain water like crazy? Are you highly reactive to sodium or cholesterol? These cues are SO much more important than the good food/bad food dichotomy because these experiences are highly personal and can’t be generalized like this.

My take? There’s no such thing as bad food, but there is such a thing as too much food. Moderation moderation moderation!

How long until my metabolism drops from fasting?

I think I know where this information came from – The Minnesota Starvation StudyMatchstick Molly does a great breakdown of this study, but in essence they took a bunch of middle aged, totally healthy guys and over the course of 6 months studied how they responded to a diet that was 50% of their daily intake needs. Basically, if the men required 2,000 calories a day to survive, they put them on 1,000 calories a day. What did they find? Their metabolism decreased by 40% – something that stayed that way for about 8 weeks after normalizing the diet. But this is a topic for another part of the metabolism series, so we’ll come back to that. This “fact” is talking about fasting after all!

How long does one need to fast before their BMR (basal metabolic rate, i.e. the amount of calories it takes you keep you alive if you lay in bed all day and don’t move) drops?

This study found that after 3 days of starvation (i.e. no food, just water) your metabolic rate INCREASES, in fact by about 1 kJ/minute (1kJ = .239 calories). This study also shows the same thing – 36 hours into the fast the BMR INCREASED, at 72 hours the BMR was about the same as it was 12 hours into the fast.

It’s not all roses and sunshine though – this study took a few healthy weight females and put them on a 48 hours fast, then measured how they responded to refeeding. It showed that 40-90 minutes after being fed after the 48 hour fast their body had a decreased metabolic rate. This means the thermogenic property of food (covered in future articles of this series) wasn’t as high as it was in other people who didn’t fast. Still: no 40% decrease in metabolism after 12 hours of fasting.

When does your BMR decrease, though? I mean, it can’t just rev and rev away, otherwise you’d die ASAP.This study shows an 8% decrease after 74 hours. So it took 3 days of ZERO food for your BMR to drop a measly 8%.

Another study for your reading can be found here. This one found your BMR increases 3.6% after a 48 hour fast. This is old hat now- you guys know this. BMR increases, then decreases after 74 hours by 8%.

Moral of the story? Your BMR will initially increase during the first 3 days of fasting by about 3-4%, then it will decrease 8% after 3 days of fasting.

I’m calling this “40% decrease in metabolism after 12 hours” a big fat FALSE.

Do you have to eat every 3-4 hours to increase your metabolism?

This broke my heart, because I am the Queen of eating every few hours. Initially I was really only hungry 3 times a day, but in every magazine I read it said to eat small meals every 3-4 hours. Now I need to eat every few hours or else I feel like I’m starving. But enough about me, let’s talk about how false this is.

This study is my favorite. They took a few obese women and put them on a 1,000 calorie a day diet. Some of the women ate the 1,000 calories in two 500 calorie meals, the other group ate the 1,000 calories split up over the day. What did they find? At the end of 4 weeks the weight loss was the same in the two groups – they lost about the same amount of fat, muscle, etc. They found that the energy expenditure and the diet-induced thermogenesis (what people THINK is an increase in metabolism when you eat multiple times a day) were the same in the two groups. The most interesting part of the study, however, was that after 4 weeks the “nibbling” group had a decrease in sleeping metabolic rate. So the group that ate twice a day had a higher metabolism at night while asleep than the nibbling/grazing group. This study found the exact same thing.

This study takes it a bit further. They looked at it from a weight loss and satiety perspective. Shouldn’t the people who ate multiple times a day be less hungry, and therefore have less Ghrelin, the hormone that stimulates appetite? PYY, the other hormone, does the opposite – it tells you your full. Shouldn’t people who “graze” or “nibble” have more PYY and less Ghrelin during the day? Nope. Both people who ate 3 meals a day and those who ate 3 meals + 3 snacks had the same levels of both hormones. Well, there goes that.

Kinda on the same vein another study looked at how eating 2 meals a day and eating 3 meals a day affected weight loss. Eating 3 meals a day showed an increase in 24h fat oxidation over the 2 meals, but had a lower fat oxidation at breakfast (fat oxidation = breaking down fats in the body into smaller pieces to use for energy). Not surprisingly they found that the people reported feeling more satiated over 24hours with 3 meals a day than 2. However, this differed from the previous study which measured levels of the hormones responsible for these feelings. In this study, they asked the subjects, meaning this finding may be just based on people being used to eating multiple times a day, or the thought of not eating, etc. If you read the conclusion of the study they get all sciencey and brainy on it, I’ll let you make your own decisions.

This study may be where this information of 3-4 hours comes from. It shows that people who nibble/graze have the same level of carbohydrate and fat oxidation during the day. There is no “spike” in metabolism or carb or fat oxidation, it’s pretty much the same all day. People who eat 2/3x a day have peaks, which are compensatory. For example, carbohydrate oxidation is increased after first meal (hearing “breakfast is the most important meal” anyone?) and was decreased over the fasting period (last meal of the night to first meal in the morning). HOWEVER: during the time your carbohydrate oxidation is low, your fat oxidation is HIGH to compensate for energy. So while breakfast proponents tout that your carbohydrate oxidation is low and you need to boost it, they kind of ignore that your fat oxidation is high to compensate. Your body is a well oiled machine guys!

Moral of this story? As long as you eat in a deficit, it doesn’t matter how many times a day you eat. Your metabolism doesn’t “boost” when you eat multiple times a day. Your BMR is your BMR whether you eat 100 calories every 2 hours or a few 500 calorie meals a day. My take? Eat when you’re hungry. It’s a crazy concept, but do it.