Wednesday, December 28, 2011

Questions And Answers: Trans Fat

What are trans fats?

Trans fats are man made fats.  They are produced through the commercial hydrogenation of unsaturated oils.  Hydrogen is bubbled through the oil at high pressure in the presence of a nickel catalyst to change the structure of the chemical bonds in the oil from cis to trans.

Why do food manufacturers do this?

Hydrogenation removes essential fatty acids such as linoleic acid and alpha linolenic acid.
These fatty acids tend to oxidize over time, which can turn the fat rancid.  Therefore, a big reason why oils are hydrogenated is to increase the shelf life of the food product.  Hydrogenation also increases the melting point of oil so that the product is solid at 25° Celsius.  This acts to improve the texture and consistency of many commercially prepared foods.  Finally, using this type of oil is cheaper for the manufacturer. 

Where are trans fats found?

Trans fats are generally found in fried foods, margarines and commercially prepared baked goods like cookies, candies and cakes.   Thankfully, recent legislation has banned the use of trans fat in restaurants in many states.  It is getting harder and harder to find them, even in food products that used to contain them a few years ago.  However, they are still used and you need to become aware of which manufacturers continue to use them in their products.

What are the health effects of trans fats?

Trans fats have been shown in the research literature to have a number of negative health effects.  They raise LDL cholesterol and lower HDL cholesterol levels, which can have a devastating impact on risk of heart disease.  Trans fats have also been associated with an increased risk of type 2 diabetes and possibly some cancers.

How do you know if a food contains trans fats?

Labeling laws now require the listing of trans fats on all food products.  This is great, not only because you can readily identify trans fat content, but because many manufacturers are now eliminating trans fat from their products so that they will not be perceived as unhealthy.  However, if a food contains less than 0.5 grams of trans fat in a serving, the manufacturer is legally allowed to list trans fats as zero grams.  This is problematic because even tiny amounts of trans fat are really harmful.  So, after checking the food label under trans fat for zero grams, you’ll also need to check the ingredient list as well.  If you see “partially hydrogenated” before any oil (IE, partially hydrogenated soybean oil) the product contains trans fat.

What are you recommendations for trans fat?

Avoid it 100%.  Treat it as if it will make you sick and shorten your life, because that is exactly what it has the potential to do.  If I was asked what is the bottom line worst thing that you can eat for your health, I would not hesitate to identify trans fat.

Wednesday, December 14, 2011

Book Review: Eat To Live

Eat To Live is next up for review.  The author, Dr. Joel Fuhrman, is a Medical Doctor who is board certified as a family physician and has also published some nutrition research. 

Introduction
            The Eat To Live program is based on several premises:
            1) The concept of nutrient density, which in simplest terms, is a foods ratio of nutrients to calories.  If a food delivers a lot of nutrients per serving, it is considered high nutrient density.  If it delivers a small amount of nutrients in a serving, it is low nutrient density.  The focus of Eat To Live is to eat only high nutrient density foods.

            2) All animal products will make you sick.

            3) All sources of dietary fat will make you sick and overweight.

            The book spends a lot of time discussing how nutrition impacts health and disease risk.  The food guidelines are then presented with a couple of 7 day meal plans and a large number of recipes.  The book is well written and an easy read. 

5 Things I Liked About Eat To Live
1) The concept of nutrient density- Eating nutrient dense foods means more fruits and vegetables and less processed junk food.  I’m all for that.

2) Strongly against sugar and refined carbohydrates- I couldn’t agree more.

3) Strongly in favor of fruits and vegetables- Fruits and vegetables are probably the best things you can eat to improve your health and the more the merrier.

4) Against dairy- I’m not convinced that dairy is a natural food for humans.  Those of you who work with me or read my book know this.  I don’t think there is a need for total elimination, but I feel that dairy intake should be now and again rather than a dietary staple.

5) Against snacking- I’ve been telling my clients not to snack for years.  If you are eating a blood sugar stabilizing diet, you should not be hungry in between meals.  Also, keep in mind that if you eat 70 more calories a day than your body needs, you’ll put on 8 pounds in a year and 23 pounds in 3 years.  Snack calories can add up like crazy over time.

What I didn’t agree with in Eat To Live
1) Very little attention was paid to exercise- I am more than convinced that for long term weight loss, cardiovascular exercise and resistance training are pivotal.   The research bears this out, as does my 15 years of working with weight loss clients.  Exercise was barely mentioned in this book and almost seemed to be an optional part of the program.

2) Unrealistic weight loss goals- Several testimonials were presented throughout the book that showed dramatic weight loss.  Some of these cases lost up to 19 pounds in 2 weeks.  Dr. Fuhrman says you should expect to lose 14 pounds in the first 14 days.  I think this is an unrealistic goal.  A pound of fat is 3500 calories.  To lose even 1 pound a week you have to create a caloric/exercise deficit of 500 calories per day.  This is not easy.  If you are losing a pound a week you are doing great.  Going into a program expecting to lose a pound a day will only set you up for failure and disappointment.  Realistic expectations can be the difference between staying with your program and giving up because “it’s not working”.

3) Incomplete evaluation of the current research- Many parts of this book are really well researched.  When describing the dangers of refined carbohydrates, saturated fats, Tran’s fats, etc, excellent research is presented.  The Nurses’ Health Study and the Health Professional Follow-up Study are mentioned several times in these sections.  These are Harvard cohorts and although I’m biased, I believe they represent the very best in epidemiological study design.

However, when Dr Fuhrman starts to mention that all animal protein promotes disease (even lean sources like chicken and fish) and all fat makes you fat (including healthy vegetable oils like olive oil and canola oil), he leaves out results from these cohorts that prove otherwise.  Research in the Nurses’ Health Study and Health Professional Study show that total fat is not associated with weight gain, that vegetable sources of fat reduce risk of disease and that lean sources of protein (including fish, chicken and turkey) are health promoting, particularly when they replace refined carbohydrate in the diet. 

4) Inclusion of many high glycemic load foods.   One of the goals of any healthy diet is to limit high glycemic load foods.  There is no mention of the concept of glycemic load in this book and the meal plans allows for daily consumption of white potatoes, fruit juice, dried fruit and you are even allowed 100 calories of cookies or candy each day if you want.  These high glyemic load carbs would be particularly damaging to the blood sugar since this diet is so low in fat and protein, which act to attenuate the glycemic response.

5) Overgeneralization of the macronutrients. Dr. Furman says that all fats and all animal protein are unhealthy and will lead to disease and overweight.  I beg to differ.  Some fats are bad for you and some are actually quite good for you.  Trans fat and saturated fat should be avoided while poly- and monounsaturated fat have been shown to reduce risk of chronic disease.  They also serve to lower the glyemic load of the diet when they replace refined carbohydrate foods and can improve health in this way as well. 

Fatty sources of animal protein like steak, sausage, hot dogs and bacon are indeed unhealthy choices and should be strictly limited.  However, fish, chicken, eggs and turkey are great choices that can actually reduce your risk of disease when they replace refined carbohydrate foods in the diet and thus act to lower the overall glycemic load of the diet.  Eating lean protein also promotes satiety, which is a big reason why my weight loss clients are not hungry between meals.

Is Eat To Live Worth Reading?
Absolutely.  If you are interested in nutrition as a profession or for your own personal health, read as many books as you can.   I think it is important to get as many different perspectives as possible.  In Eat To Live you will learn a lot of great things about the benefits of fruits, vegetables, whole grains and legumes.  You’ll also learn a lot about the dangers of refined carbohydrates, saturated fat and Trans fat. 

Will you lose weight?  I think you will, at least in the short term.  This is a really low calorie diet.  However, low fat diets are just too hard to stay on for any length of time and the research shows that most weight lost on low fat diets is regained after about a year.  Just keep in mind as you read this that a healthy diet also includes a bit more protein (even some lean animal protein like chicken, eggs, fish and turkey) and a lot more healthy fat (like olive oil, canola oil, nuts, avocado, etc).  Also keep in mind that if you truly want to lose weight and keep it off, exercise is a huge part of the equation.  We all collectively must learn to accept this basic truth.