Sunday, June 7, 2009

The American Paradox

Stephan over at Whole Health Source is doing a series on Omega-6 and its possible role in the heart disease epidemic of the 20th century. This inspired me to put a series of sample daily menus into Fitday to see just how much omega-6 average people with different types of diet might actually be eating.

First up is an individual who is not health-conscious. An example might be a young (male) student. He starts the day with a bowl of sweet cereal (cocoa puffs) with milk and sugar. Then lunch is a chicken roll (actually I chose a Subway Sub- but only 6"). For snacks during the day he eats a bag of potato chips and a Snickers bar. In the evening, he shares a pizza with mates, followed by some ice-cream. He drinks soft drinks as well as coffee and all the milk (and ice-cream) is full-fat.

Not surprisingly this diet is high calorie (3205 kcal) and high-fat (although not as high-fat as my diet!): 40% fat (144g) by energy, 48% (394g) carbohydrate (which is within the average minimum daily recommendation (45-60%) of the 2005 dietary guidelines) and only 13% protein (106g). What is surprising is that, according to Fitday, such a menu contributes only 13% of calories as saturated fat - putting it close to the recommendation (less than 10%); 10% as monounsaturated fat and a whopping 13% fat as polyunsaturated fat. Most of that polyunsaturated fat will likely by omega-6 fatty acids as its source is the vegetable oils which are ubiquitous in processed foods. This indiviudal's body cell membranes will be saturated with omega-6 fats as in Stephan's graph here.

If you eat processed foods, the only way to get your omega-6 polyunsaturates down would seem to be by eating a very low fat diet. Here is my 'extremely health-conscious low-fat eater's' diet. This lady starts the day with oatmeal porridge made with water, followed by multigrain toast with a smear of honey. She always puts skim milk in her tea and coffee and doesn't take sugar. A home-made chicken (breast meat, no skin!) and salad sandwich is followed by an apple. Although she succumbs to an oatmeal cookie with her cup of tea, dinner is a healthy chicken and vegetable affair on wholewheat macaroni, followed by a banana and light ice-cream. Trouble is she's hungry later, so it's a non-fat yoghurt and a small bowl of muesli (skim milk of course) just before bed.

Actually, I had to add those snacks in, not only because our subject might be hungry due to the lack of fat and overload of carbohydrates but just to get the calories up above starvation levels to a respectable 1842 kcal. This diet is 22% fat (46g), 61% carbohydrate (294g) and 17% protein (80g). It has only 5% of total calories as saturated fat, 8% as monounsaturated fat and 6% as polyunsaturated fat. So even with a diet meeting the 2005 dietary guideline recommendation for carbohydrate and fat intake (20-35%), the intake of polyunsaturated fat is above the level which may cause problems if it is predominantly omega-6 as explained here.

What about someone in between those two extremes? Here is someone who is trying to eat 'healthily' but not always succeeding. This person starts the day with 'heart-healthy' Cheerios with 2% fat milk and some toast with jam, but is hungry by mid-morning so succumbs to a muffin with a Latte coffee. H/she also eats a chicken and salad sandwich for lunch - but not necessarily home-made - and an apple. Hungry in the afternoon, a diet brownie is eaten. Dinner is chicken in a cheese sauce with macaroni (white not wholewheat) and a green and tomato salad with a commercial dressing, followed by some tinned fruit and light ice-cream.

This diet is 2176 kcal and still within dietary guidelines: 30% fat (75g) and 55% carbohydrate (302g) and about the same amount of protein (80g) or 15% by energy as in the low-fat diet. Once again, polyunsaturated fat is high - 10% , equal to the proportion of monounsaturated fat, and thanks to all the innovative processed foods eaten, saturated fat consumption is well within the dietary recommendation target at only 8%.

So this is the American paradox. Thanks to the processed foods now available, saturated fat consumption has been reduced towards target. Even the least health conscious can now eat pizzas, snack foods and chocolate bars and be approaching the holy grail of 10% of calories! The public have long been doing their bit to get their carbohydrate consumption up to above 50% - that part is easy since carbohydrates are really quite addictive. So why are there still health problems, why is there still overweight and obesity? That is the American paradox.

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