Monday, March 31, 2008

A degree in obesity


We know we’re currently experiencing an “obesity epidemic” so it was just a matter of time before we could get a degree in it, right?

The degree is being offered for the first time this fall through the University of Guelph and Humber College and graduates will gain knowledge of obesity-related illnesses like heart disease and diabetes, develop the skills to become personal fitness and nutrition instructors, learn how to conduct physical assessments and to develop exercise and nutrition plans tailored for clients with different health statuses.

The program was developed with the help of Terry Graham, a U of Guelph human health and nutritional sciences professor. She points out the obvious that “activity and nutrition influence each other with regard to health benefits, and studies have shown that these aspects of lifestyle are more effective in preventing and moderating diabetes than the best drugs."

When I was completing my university degree in dietetics, I wished we had been taught more about exercise physiology and even fitness assessments... (not to toot my own horn but I did suggest it and was rudely dismissed by the higher-ups. hmph).

During their 4 years, students will complete classes in anatomy, physiology, biophysics and biomechanics, motor learning and neural control, biochemistry, nutrition, fitness and lifestyle assessment, human development and aging, natural health products and physical activity, just to name a few. They will also complete 2 internships for that ever-important real-life experience.
Upon completion, graduates don’t become dietitians. In fact, there’s only 3 classes in nutrition: Nutrition: Exercise and Metabolism, Fundamentals of Nutrition: Pharmacaology and Toxicology and Special Populations: Exercise and Nutrition. They do get Bachelors of Applied Science in Kinesiology from U of Guelph and a diploma in fitness and health promotion from Humber. As such, they can work as kinesiologists, personal trainers, wellness consultants and fitness practitioners in clinical and rehab settings.

The response to the program has been overwhelming with more than 430 students applying for just 60 spots. Apply only if you're really smart!


Thursday, March 27, 2008

The answers are in!!

The calorie quiz answers are in!
If you haven't seen the questions yet- stop reading and check out the bottom of March 25th's post to take the quiz!

What has more calories?

1. a.
Grande Café Mocha with
whip (nonfat milk) or b. a McDonald’s Bacon Cheeseburger?
Answer is a.

The Café Mocha with whip and made with skim milk! It has 420 calories whereas the Bacon Cheeseburger has 330 calories.




2 a. McDonald's medium fries or b. a Starbucks cranberry orange scone?
Answer is b.
The scone! It has 460 calories. The medium fries has 380 calories.





3 a. A regular plate of spaghetti with meatballs at an Italian restaurant or b. a slice of Pizza Hut Meat Lover’s stuffed crust pizza (1/8 large pizza)?
Answer is a.
The plate of spaghetti with meatballs has double
the calories of the pizza slice: 1010 calories vs 500 calories for the pizza slice!




4 a. A plain bagel with 2 oz cream cheese or b. a croissant with spinach & cheese (Au Bon Pain)?
Answer is a.
The croissant has half the calories of the bagel: 250 calories in the croissant vs. 500 calories in the bagel.


5. a. A Jamba Juice Banana Berry smoothie (original size) or b. a cafeteria-style lasagna piece?
A
nswer is a.
The smoothie! The smoothie has 480 calories whereas
the lasagna piece has 275 calories.





Sooo...How'd you do?!


Sources:
http://www.starbucks.com/retail/nutrition_info.asp
The Calorie King Calorie Fat & Carbohydrate Counter, 2007.
http://www.mcdonalds.ca/en/food/calculator.aspx

Wednesday, March 26, 2008

Trans vs. Saturated Fats


Trans fats act like saturated fat by increasing "lousy" LDL cholesterol but it also decreases the "healthy" HDL cholesterol.
So, we know that trans fats are worse than saturated fats, but how much worse?

Two times.

Trans fats increase the total cholesterol to HDL cholesterol ratio (a higher cholesterol to HDL ratio is bad) nearly two times more than saturated fats.
Avoid them!

Source: Ascherio, A, Willett, WC. Health effects of trans fatty acids. Am J Clin Nutr. 66 (4 suppl). Oct 1997.

Tuesday, March 25, 2008

Calories mandatory on menus in New York.


In January, the New York City’s Board of Health voted unanimously to require all city chain restaurants (with 15 or more outlets or 10% of all city’s restaurants) to post calories on their menus by March 31 2008.

New York readers: take pictures for us, ok?!


This information will help New Yorkers make healthier choices about what to eat. The NY City Department of Health points to studies that show that 90% of people underestimate the calories in chain restaurant meals by ~600 calories. Other sources, including Brian Wansink’s work done as director of the Cornell Food and Brand Lab and documented in his book ‘Mindless Eating’, has shown that people always underestimate calories, but they get it especially wrong when they’re eating something they think is healthy, grossly underestimating calories by about 50 percent!


Similar menu labelling requirements have been adopted in King County, Wash., which includes Seattle, and are under consideration by 21 other state and local governments. Nothing yet in Canada.


This NY initiative has been very controversial. As could be predicted, The New York Restaurant Association sued the Board of Health in an attempt to block the measure, claiming it would violate its members' First Amendment rights. They also argued that consumers really don't want that information on menus because it will look too "cluttered" and that consumers can already find the information on many company Web sites. They said that other labeling laws haven't made a bit of difference to the obesity epidemic. Foods in the grocery stores have been required to list all sort of health information for years, and yet waistlines keep expanding. They lost.


Dr. David B. Allison, the incoming president of the Obesity Society, a leading organization of obesity doctors and scientists, surprisingly sided with the Restaurant association and basically said that having the calories on display could result in a “forbidden-fruit allure” of high-calorie foods or send customers away hungry enough that they will later gorge themselves even more. Huh?! This angered many of the Obesity Society members since he organization supports calorie labelling on menus and had to issue a statements in response saying: “The Obesity Society believes that more information on the caloric content of restaurant servings, not less, is in the interests of consumers.”


The new labelling rules by New York City’s Board of Health also have support from consumer groups like Public Citizen and the Center for Science in the Public Interest, as well as doctor groups like the American Medical Association, the American Academy of Pediatrics, the American
Diabetes Association and the American Heart Association.

Not so surprisingly, David Allison has since resigned. Turns out he was being paid as a consultant for the restaurant industry! He’s also worked as an advisor for companies like Coca Cola, Kraft Foods and Frito-Lay in the past. Hmmm.

Ok. Let’s see how good you are at guesstimating calories of restaurant foods!

What has more calories? (If you're feeling confident, you can try guessing how many calories each choice has too!)


1. a) Grande Café Mocha with whip with nonfat milk
b) McDonald’s Bacon Cheeseburger.


2.
a) McDonald's Medium fries
b) Cranberry Orange scone (Starbucks).


3.
a) Regular plate of spaghetti with meatballs
b)1 slice Pizza Hut Meat Lover’s stuffed crust pizza (1/8 large pizza)


4.
a) Croissant with spinach & cheese (Au Bon Pain)
b) Plain bagel with 2 oz cream cheese


5.
a) Banana Berry smoothie- original (Jamba Juice)
b) Cafeteria-style lasagna (1 piece)


Answers will be posted in a couple of days!! Stay tuned.

Sources:
http://www.nytimes.com/2008/03/04/business/04obese.html , http://www.nytimes.com/2008/02/16/business/16obese.html?fta=y , http://www.cnn.com/2008/HEALTH/diet.fitness/01/22/calories.menus/index.html , http://www.cnn.com/HEALTH/blogs/paging.dr.gupta/2008/01/counting-calories-on-fast-food-menus.html ,
http://www.cbsnews.com/stories/2007/11/16/60minutes/main3513549.shtml , The Calorie King(R) Calorie Fat & Carbohydrate Counter. 2007.

Wednesday, March 19, 2008

DHA makes smarter babies


I’ve been talking a lot about omega 3 and I’m sorry if this is of no interest to you! There was a comment (thanks Naznin!) re: DHA in breastmilk recently so I think this is an important topic to talk about.

During pregnancy, Omega 3 fats are incorporated in the fetal brain and lipids in the retina (eye). We know that the DHA form of omega 3 in particular plays an important role in optimal development of the central nervous system (ie. brain) and visual sharpness of babies. Developing infants can't efficiently make their own DHA and need to get it through their mother’s placenta during pregnancy and from breastmilk after birth.
The amount of DHA in a mother’s diet determines the amount of DHA in her breastmilk. This is why it’s important that moms and moms-to-be understand the need for them to get enough DHA in their diet. We know that Alpha-linolenic acid (
ALA) (ie. flaxseeds, walnuts) form of omega 3 isn’t well converted to DHA so the moms’ best bet is to get a direct source of DHA.


According to the International Society for the Study of Fatty Acids and Lipids working group, maternal intake of DHA should be greater or equal to 300mg. Studies have shown that the average Canadian pregnant woman’s DHA intake is only about 80mg/day.
Breastmilk is a source of DHA only if the mother’s DHA intake is adequate, which, as we’re seeing, it’s not. Nutritional education of pregnant women is necessary to fix this problem.

A reasonable explanation for why DHA intake in pregnant women is low is because DHA is found predominantly in fish/seafood, a food that is often avoided/limited by pregnant women. They’ve found that women eat fish once or so every 10 days during pregnancy because of concerns with respect to contaminants (eg, methyl-mercury in a few fish which can increase the risk of impaired brain development in the infant).

The Food and Drug Administration (U.S.) has recommended that women who are pregnant eliminate shark, swordfish, king mackerel, and golden snapper from their diets while limiting their consumption of other fish to 3 servings/week to minimize exposure to methyl mercury.

From Health Canada’s website: Predatory fish such as shark, swordfish, fresh and frozen tuna (not canned), have higher levels of mercury and should be consumed only occasionally. The health benefits of eating fish outweigh the risk of exposure to mercury if Health Canada consumption guidelines are followed. If you are an adult, limit your intake of these fish to no more than one meal per week. Pregnant women, women of child-bearing age and young children should be especially careful and limit their intake of these fish to no more than one meal a month.

A recent Canadian study found that the consumption of 2-3 servings weekly of salmon or rainbow trout, which would provide a daily averaged DHA intake of at least 300 mg/day during pregnancy, would not approach the tolerance levels for mercury, polychlorinated biphenyls, or dioxins and furans as set by Health Canada, the NRC (U.S.), or the World Health Organization.

However, if you don’t want to eat fish, algal oil (now available in capsules and just oil form) is a great source of DHA and, as I’ve blogged about previously, foods are being enriched with DHA now.

There is evidence from published clinical trials that women with higher DHA intakes (up to 1100 mg DHA daily), gave birth to infants with higher cognitive development scores and young children with higher IQ scores and mental processing scores up to 4 years of age.

A 2004 study published in Child Development found that babies whose mothers had high blood levels of DHA at delivery had advanced attention spans into their second year of life. During the first six months of life these infants were two months ahead of babies whose mothers had lower DHA levels.

Other current research suggests adequate levels of DHA may help reduce the risk of pre-term labor and decrease the risk of postpartum depression, improve babies’ sleep patterns and immunity (better allergy protection) and reduce to risk of allergic disease. Wow!

Once born, babies still need DHA and their only source of nutrition (incl. DHA) for growth and development is their mother's milk. Health Canada has reported that DHA represents an average of only 0.14% of the total fat in breast milk (due to current low DHA intakes) and it should be at least 0.35% - an amount that has been shown to result in better brain and visual functioning of infants. The direct consumption of DHA, at relatively low levels, provides a fairly rapid and marked improvement in the DHA level found in breast milk. An intake of 300 mg DHA/day during lactation has been found to elevate breast milk levels to 0.39% DHA.

Higher intakes of DHA (>200mg/day and up to 1183mg/day) during breastfeeding have resulted in babies scoring higher on cognitive tests after 30 months, greater visual development and acuity in term infants as well as optimized arousal in newborn infants.

Should moms choose DHA-fortified formula? I’ll blog about this another day but of course, breastfeeding is the best source of nutrition for your baby and also offers a plethora of other benefits! So, simple answer is: No. Increase your intake of DHA.

Sources:

http://dhaomega3.org ; http://www.ajcn.org/cgi/content/abstract/82/1/125?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=fish+oil&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT http://jn.nutrition.org/cgi/content/abstract/135/2/206 ; http://nutrition.about.com/b/2005/09/27/dha-for-smarter-babies.htm ;
http://www.drlaura.com/sah/sahm.html?mode=view&tile=1&id=10576 ;
;
http://www.hc-sc.gc.ca/iyh-vsv/environ/merc_e.html

Monday, March 17, 2008

Did you know...



Did you know that someone living in New York could eat out every night of their life and never eat at the same restaurant?

Maybe my New York readers could test this one out for me?

Source: http://www.strange-facts.com/

Sunday, March 16, 2008

What's Salba?


I first heard about Salba® through an email my mom received from a colleague of hers about a month ago. A few weeks later, a colleague of mine asked me if I had heard about Salba®. And since then, I've been hearing, and seeing, Salba® everywhere. A few weeks ago, while I was in Loblaws, I saw a cereal called Omega 3 granola, from President's Choice. It caught my eye and I looked at the ingredient list to find out what the omega-3 source was and lo and behold, it was Salba®!

What is Salba®?

Salba® is a trademark name for a very old seed called Chia (the white seed, not the black seed). Yup, chia as in the seeds used in Chia Pets!

Chia is a very ancient grain that was once a staple in the Aztec diet and is derived from the plant called Salvia hispanica L.

On the Salba® website, they compare Salba®, gram for gram, to normal foods. Below are their claims but it makes more sense to compare real measures. Chances are you wouldn’t consume much more than 2 Tbsp Salba® per day (12g), so let’s compare 12 g Salba® to real portions of other foods.


Salba® health claims on Salba® website.

Salba® has....

Salba® (12g) nutrients

Nutrients of real portions of foods

1.5 x more magnesium than broccoli

46mg

18mg for ½ cup broccoli

1.1 times more fibre than All Bran

4g

12g for ½ cup

2.5 times more protein than kidney beans

3g

7g for ½ cup kidney beans

8 times more omega 3 than Salmon

2.5g

2.58 g for 4oz salmon

3 times more iron than spinach

0.95mg

1.6 mg 1cup raw spinach

2 times more potassium than a banana.

80mg

454mg for 1 banana

7 times more vitamin C than an orange

0.65mg

70mg for 1 orange

6 times more calcium than milk

92mg

319 mg for 1 cup milk

As you can see, the nutrition claims aren’t as dramatic when compared this way!

It’s also important to remember that the omega 3 is in the alpha-linolenic acid (ALA) form and not the more beneficial DHA form that’s found in fish or algae.

The website further claims that Salba® is the only type of Salvia hispanica L. that has undergone intensive clinical examination. To my knowledge though, there has been only one study done on Salba® (see below) and only 20 people participated in it!

They also claim that: “In acute and long-term clinical studies conducted on individuals with Type 2 Diabetes, Salba® reduced after-meal blood glucose and plasma insulin levels, thereby improving insulin sensitivity, reduced blood pressure, and was effective in reducing risk factors of heart disease, such as body inflammation (C-reactive protein (CRP) and coagulation factors (aspirin-like effect)”. Let’s look at this study:

For some reason ($?), a Toronto doctor, Vladimir Vuksan, and his team at St. Michaels decided to uncover the magic behind this seed and have published their results in Diabetes Care last year. Their research is the only one done on Salba® and, interestingly, Dr. Vuksan holds the patent on Salba®. Wouldn’t you say there’s a bit of conflict of interest involved? I would!

Their study was meant to determine if people with Type 2 diabetes that took Salba® along with conventional treatments had improvements in the cardiovascular risk factors.

27 eligible subjects were enrolled in the study but only 20 people with Type 2 diabetes were included in the final analysis.

The participants were randomly given either 15g/1000 calories of Salba® or the same amount of wheat bran (which, supposedly, has little effect in glucose tolerance). They were also instructed on following a diet recommended by the Canadian Diabetes Association that focuses on low glycemic foods, a 55% carb, 15% protein and 30% fat diet and 25-35g fibre diet. They were also told to maintain their normal medication therapies (which varied between participants). They stayed on the ‘treatment’ for 12 weeks. Then there was a ‘washout phase’ of 6-8 weeks and then the participants switched treatments (the Salba® people now took wheat bran and vice versa).

Interestingly, despite the claim that Salba® reduced after-meal blood glucose and plasma insulin levels and therefore improved insulin sensitivity, fasting blood glucose, AIC and fasting insulin were not significantly different at the end of the treatment phase OR when compared to the control (wheat bran) group!

Blood lipids were also not different between the Salba® group and the control group. As for the claim that Salba® is effective in reducing risk factors of heart disease, such as body inflammation (C-reactive protein (CRP)); the control wheat bran phase compared with the end of the Salba® phase. However, omega 3- both DHA found in fish and ALA found in ground flaxseeds have been shown to decrease inflammation.

The claim that Salba® has an aspirin-like effect is a bit deceiving because although the Salba® group did experience thinning of the blood, so did the wheat bran group- so there was no significant differences between the 2 groups.

A couple of other problems with the study:

Very small study group and relatively short study period. Physical activity during the study was not quantified, which might bias the results.

So, all in all, there is very little research to back up the health claims behind Salba® and any result is marred by the fact that the main researcher owns the patent on Salba®!

Not worth the cost, in my opinion. But if you want to try it, click here to order a sample: http://www.sourcesalba.com/contact-us-sample.php

According to the website, Salba® does not have to be ground up to get the benefits. It should be stored in a dry cool place, like flaxseeds. Because of its thinning effect on the blood, talk to your doctor before trying it.

Sources: http://www.sourcesalba.com/ ; http://www.salba.info/patent.html ; http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20071115/salba_071115/20071115/ ; http://care.diabetesjournals.org/cgi/content/full/30/11/2804

Thursday, March 13, 2008

DHA + EPA in some foods


From my Fish vs Flax blog, we learned that all omega 3s aren’t created equally. It’s the DHA and EPA that are linked to a lower risk of heart disease, cancer, Alzheimer’s disease, eye disorders and other health problems. ALA (alpha-linolenic acid), although high in fibre, isn’t as beneficial. The conversion from ALA to EPA is low but is better than the conversion of ALA to DHA.

Generally, you should be aiming for 500mg (0.5g) DHA and EPA a day. Remember that intakes of 650-700mg DHA and EPA a day has been correlated with a reduced risk of coronary heart disease. If you have heart disease, you should be aiming for 900mg/day. If you’re pregnant or breastfeeding, aim for a minimum of 300mg a day.

Included below is the amount of DHA and EPA in different fish and other products if you don’t eat fish. I’ll talk about some of the Brand-name products below. Note that considerable differences may exist with respect to the reported levels of DHA and EPA, even for a given fish source, due to various factors (ie. geographical origin).

FOOD (170g for fish unless noted)

DHA+EPA (mg)

FOOD (170g for fish unless noted)

DHA+EPA (mg)

Atlantic salmon, farmed

3650

Scallops

620

Atlantic salmon, wild

3130

Skipjack tuna, fresh

560

Gold Seal Pacific Sockeye Salmon (100g)

2900

Pacific cod or yellowfin tuna, fresh

470

Compliments Sliced Smoked Atlantic Salmon (55g)

2450

Blue crab (85g) or haddock

400

Gold Seal Pacific Pink Salmon (100g)

2400

Catfish, wild

400

Coho salmon, farmed

2180

V-Pure algae supplements (3)**

270 mg DHA/89 mg EPA

Rainbow trout, farmed

1960

Shrimp (85g) or Atlantic cod

270

Coho Salmon, wild

1800

Naturegg Break-Free Omega 3 Liquid Eggs (50mL, 1 egg)

250

Rainbow trout, wild

1670

Clams (85g)

240

Swordfish

1390

Naturegg Omega Pro Large Eggs (1)

130*

Sardines (in tomato sauce) (85g)

1190

Naturegg Omega 3 Large Eggs (1)

80

Pacific oysters (85g)

1170

Lobster (85g)

70

Mackerel, canned (85g)

1050

Becel Omega 3plus margarine 2tsp

50

Compliments Smoked Wild Sockeye Salmon (55g)

900

President’s Choice Blue Menu Oh Mega j Orange Juice (1cup)

50

Pollock or whiting

900

Danone Danino Yogourt with DHA (100g)

40*

Flounder or sole

850

Silk Plus Omega 3 DHA Fortified Soy beverage (1cup)

30*

Sardines in vegetable oil, drained (85g)

840

Egg (1 large)

20

Halibut

790

Minute Maid Fruit Solutions Omega-3 Orange juice

20*

Rockfish

750

Tropicana Essentials Omega-3 Orange juice (1 cup)

20*

Fish sticks (6)

680

Neilson Dairy Oh! 1% milk with DHA

10*

* DHA only.
** V-Pure supplement is the first vegan source of DHA and EPA, is made from algae and is recommended by Vesanto Melina, RD specializing in vegetarian and vegan nutrition.

Many brand name products are jumping onto the omega-3 bandwagon and claiming their products are great sources of omega 3. Maybe... but remember to read the ingredient list and NOT the nutrition facts table to find out the omega 3 source. This will tell you if the product has any DHA.

If you see fish oil or algal oil, the product has DHA. We'll look at 2 products today:

Silk Plus Omega-3 DHA Fortified soy milk: The ingredient list show the product has both flaxseed oil and algal oil. So the product contains some DHA. The nutrition facts table says that 1 cup provides 400mg of omega 3- but the small print indicates that only 300mg of that is DHA. Many other ‘Omega-3’ soymilks have no DHA so be aware.

Omega 3 eggs. Many eggs now have omega 3- the chickens are fed flaxseeds and they actually convert some of that ALA to DHA. Some packages tell you how much DHA is present in one egg, some don’t. On average, omega 3 eggs have about 75mg of DHA. However, this DHA doesn’t compensate for the high cholesterol found in the egg yolks (average of 210mg/yolk). Omega 3 eggs have pretty much the same amount of fat and cholesterol than regular eggs and cost 3 times as much. Although recent research has found that total fat and saturated fat have a greater impact on our cholesterol than cholesterol, the Heart and Stroke Foundation of Canada still recommends 2 egg yolks/week. These omega-3 eggs are not worth it, in my opinion.

Sources: http://dhaomega3.org/ ; Liebman, B. Omega Medicine: is fish oil good for what ails you? Nutrition Action Health Letter. Vol 34: 8, Oct 2007 ; http://www.nutrispeak.com/omega_3s__epa___dha.htm ; http://www.lesliebeck.com/ingredient_index.php?featured_food=21

Wednesday, March 12, 2008

Did you know...

A new regular addition to my blog will be a 'Did you know...' entry: fun (and weird) food facts.
I'm not sure how reliable the sources are, but it's just for fun!

Did you know that American Airlines saved $40,000 in 1987 by eliminating one olive from each salad in first class.


Tuesday, March 11, 2008

My Big Fat Diet


Did you watch 'My Big Fat Diet' on CBC tonight?

We know that obesity and Type 2 diabetes is prevalent among the aboriginal population. According to some sources, its 5 times the national average. Their genetic predisposition combined with their change of diet (introduction of the Wesern diet into their communities) and lifestyle (now more sedentary) is undoubtedly the culprit.

Dr. Jay Wortman, a métis doctor and a Type 2 diabetic himself, noticed that when he cut out carbohydrates (starches and sugars) from his own diet, his blood sugar and blood pressure normalized.
He decided to design a study where he'd get 100 members of the Namgis First Nation from Alert Bay, BC to cut out all carbohydrates from their diet- all starches as well as fruit and milk- for one year. The study was funded by UBC and Health Canada and is still being evaluated.

The study diet is supposed to be based on a traditional native diet but also includes modern market foods.

Any meat was permitted as part of the diet- beef, pork, chicken, fish and seafood- as well as bacon, eggs, butter. Participants were also allowed up to 2 cups lettuce/day, 1 cup veggies per day, 4oz cheese/day. Oolichan grease (made from small smelt-like fish that are supposedly high in monounsaturated fats) was allowed and encouraged as part of the diet.

In my opinion, this is quite far from a "traditional" diet.

Food not permitted include starches like breads, pastas, rice, potatoes, as well as lactose (milk products including fresh cheese) and fructose (fruits).

From what I gathered from the documentary, adherence to the diet was determined only by interview. In fact, participants did admit to cheating, a few almost bingeing on cookies and tarts at times. One participant, a recovering alcoholic, said the cravings were so bad that he implemented the same 12-step program that he had used to deal with his alcoholism!

I noticed that some participants had cranberries and squash so it seems that the diet wasn't void of carbs... The macronutrient breakdown of the diet was not released (not sure if it was calculated).

One participant underwent open heart surgery during the study because he had 80% blockage- but he claims he had heart disease before starting the diet. Another participant dropped out because of high reflux (couldn't tolerate the high fat content).

86 people participated in the study initially but 29 dropped out. At the time of analysis, 40 people had stayed on the program for at least 4 months. These 40 people lost an average of 10kg, which is significant. Their blood pressure did increase slightly (not significantly though). Triglycerides decreased by ~20%, which was significant and probably predictable due to the drastic reduction of carbs. HDL (good cholesterol) went up a significant 17.5%, LDL (bad cholesterol) went up 2.2%, which was not significant. Total cholesterol:HDL ratio decreased 11.5% (significant). Hemoglobin A1C (average blood glucose over 3 months) also decreased.

All in all, these initial findings are promising... But what will happen in the long run? Will participants drop off the diet due to the fact that most foods are restricted? What about the long-term consequences of a high fat diet?
Physical activity did not seem to be part of the study outline, which is too bad.

What's interesting is Dr. Wortman's response to the question: Will a low-carb diet increase my risk of heart disease?

I'll copy his answer from his blog:

This is another common myth. It is based on the notion that if you eliminate carbs as an energy source you will have to increase fat intake to compensate (there is a limit to how much protein you can eat). It was thought that an increase in fat would lead to high cholesterol which is associated with heart disease. When the studies were actually done on this, however, much to everyone’s surprise, the opposite happened. People on a low-carb diet improved their cholesterol readings even when they increased their fat intake and even when their intake of saturated fat (the so-called bad fat) increased. It appears that when you body must rely on fat for energy, the saturated fat you eat gets burned up before it can cause any harm. Another factor that plays a role in heart disease is the level of inflammation in our system. If the markers of inflammation are high we recognize this as a sign of increased risk of heart disease. We commonly order a C-reactive protein test, a marker of inflammation in the blood, to assess a person’s risk. A recent study showed that people on a low-carb diet demonstrated significantly reduced inflammatory markers.

Although there haven’t been any long term studies yet to prove it, the existing science suggests that a low-carb high-fat diet may actually reduce the risk of heart disease.

I think the fact that no long-term studies have been done is important to note.
I also need to research more on the need of carbohydrates in our diet. As dietitians, we learn that our brains and bodies need glucose (from carbs) to function. If we don't get it from our diet, first our livers release its stored glucose and then our bodies break down fat and muscle that can be converted to glucose, but this results in ketones that are toxic to our bodies. Dr. Wortman states that this too is a myth. In his blog, he writes that our body is quite happy to burn ketones to meet energy needs and the amount of ketones produced isn't enough to cause any harm!

In my opinion, there must be a minimum amount of carbs that we need to get from our diet... Nonetheless, I think there is merit to the fact that a reduction in carbs can be helpful in managing diabetes and improving lipid profiles, I'm just not sure what that magic number is.
An analysis of pooled data from 13 studies has shown that a decrease of carbohydrates in the diet from 65% of calories to 35% showed improvements in Type 2 diabetes management and a 23% drop in triglycerides. However, restricted carbohydrate intake didn't result in a significant reduction in body weight.

According to Leslie Beck, RD, t
he minimum recommended daily allowance for carbohydrates is 130g per day for adults based on the minimum amount of glucose needed to feed the brain each day. This amount equals 43% of calories in a 1,200-calorie diet; 30% of calories in a 1,700-calorie diet and 24% of calories in a 2,200-calorie diet.

Sources: http://www.drjaywortman.com/blog/wordpress/about/ ; http://www.cbc.ca/thelens/bigfatdiet/wortman.html
http://www.lesliebeck.com/page.php?id=2508&type=art

Fat loss & Muscle gain


A frequent commenter on my blog, Jme asked the following question:

What if I do not want to lose ANY muscle while trying to lose fat? Then what intensity and duration would be good for me?

This is my answer:

The best way to gain muscle (or prevent muscle loss) is to lift weights. The optimal way to burn calories (lose weight) is to do aerobic activity (but I know you knew that!).

(Because nutrition wasn't part of the question, I'm not going to talk about that today. Suffice to say that macronutrient breakdown doen't change much between exercisers and non-exerciser: ~50% calories from carbs, ~20% from protein and <30%).

There's no research available to predict what percent of weight gain or loss is muscle and how much is fat. The best tool you can use to know you're losing fat and building/maintaining muscle is to have your body composition measured and to re-measure it every 1-3 months. It's a great tool to have to track your progress.

Remember that calipers are not as accurate as bioimpedence measurements (these are the 2 that are more common- there are better methods available though).

Body fat percentage normally changes slightly over time, but only by 1 or 2% over several months.

You have to work to maintain muscle and if you don't work out, your body looses muscle and deposits more fat if you continue to eat the same amount of food.

As for intensity of aerobic activity, it depends on your current fitness level.

A beginner (very low to low level of fitness) can lose weight and improve fitness level by exercising 1-3 times a week at 55-64% of their Max HR*.

A person of average fitness should exercise 3-5 times a week at 65-74% of their Max HR* to see some weight loss and see some improvements in fitness level.

A competitive athlete's goals are generally a bit different in that weight loss is secondary to improving performance (VO2max), competition and training. It's generally recommended that competitive athletes not focus on weight loss too much as that may affect performance.

In order to meet training goals, these athletes should workout 4-7 times a week at 75-90% MaxHR*.

Of course, these are just a general guidelines and can vary depending on training goals and sport.

In terms of resistance training, common goals include wanting to build muscle, muscle definition and to improve overall functional strength and power.
If you want to maintain your muscle mass and develop definition and endurance, it's recommended that you work at an intensity of 70% or less of your 1 RM** (Repetition Maximum- the max amout of resistance you can lift one time) and lift between 12-20 repetitions.

If building muscle is a goal for you, you should be working at ~80% of 1RM** and perform 6-10 reps.

If increasing power is a goal for you, lift at 100% 1RM**!

The more sets you do, the more you fatigue your muscle fibres, the more you encourage muscle growth during the recovery stage. So, if muscle building is a goal for you, use multiple sets. If you're new to lifting weights, current research shows that you can see results with 1 set of each exercise.

Fibre type is also important when talking about resistance training. Slow twitch fibres are the ones that provide most of the movement during low-intensity, long duration activities (50-70% of your 1RM**). To recruit the fast-twitch fibres that that capable of muscle growth, you should exercise with greater force or at higher intensities (>70% of 1 RM**).

Hope this answered your question, Jme!

* To calculate your Target Heart Rate, use the Heart Rate Reserve Method:
Max HR= 220-age

Target HR= {(Max HR-Resting HR) x Range(%) + Resting HR}
Ex. 40 year old with a resting HR of 68 BPM exercising at 60% :
Target HR= {(220-40) – 68 x (0.60) + 68}
Target HR = 135 BPM

** To find your 1RM and % of your 1RM, visit:
http://www.exrx.net/Calculators/OneRepMax.html

Source: Hutton, J. CanFit Pro Personal Trainer Specialist Certification Manual. Toronto: CanFitPro.