Help for the webtool

This webtool calculates the effect of dietary changes on blood lipids and lipoproteins in humans. It is based on the combined outcomes of many well-controlled dietary trials in groups of volunteers (see References).

The tool has three steps.

step 1: nutrient entry

Here you enter nutrient intake data for two or more diets. You need to enter data for at least two diets, because the webtool calculates changes in blood lipids when the diet is changed. You may enter diet names, e.g. 'initial' and 'final', or 'American' and 'Japanese'.

You can enter fatty acids or fatty acid classes, cholesterol, and protein. You can enter a few or only one nutrient, e.g. trans fatty acids, and leave the rest blank. If you enter a nutrient for one diet you must also enter that nutrient for the other diet(s).

If you do not balance changes in one macronutrient with changes in another macronutrient the webtool will make up changes in % of energy from fatty acids or protein with calories from carbohydrates. For example:

1. Diet 1: saturated fat 20% of energy. diet 2: saturated fat 5% of energy. You do not specify what calorie source replaces saturated fat. The webtool now assumes that you replace 15% of energy as saturated fat by carbohydrates.
2. Diet1: saturated fat 20% of energy, mono-unsaturated fat 10% of energy. Diet 2: saturated fat 5% of energy, mono-unsaturated fat 25% of energy. The webtool now assumes that you replace 15% of eenergy as saturated fat by mono-unsaturated fat.

If you select the webtool will ignore entries for total saturated fatty acids, and vice versa

You can enter fatty acid consumption as % of energy (% of daily calories), gram per day, or % of fatty acids. If you enter a unit other than % of energy the webtool will query you for total fat or total energy intake. These queries pop up or disappear when you change the units in which you enter fatty acid intakes. If you do not enter values for total fat or total energy intake when queried the webtool cannot proceed. The webtool can calculate total energy (total calories) from carbohydrate, protein, fat, and alcohol intake.

When you are done you click Next, and step 2 will appear.

step 2: confirm entered data

In step 2 the webtool shows you what you have entered. It also shows you how it has recalculated grams per day or % fatty acids into % of energy. Nutrients that are unchanged show up as 0. You can go back and edit your input, or you can Confirm it. Clicking Confirm will open step 3.

step 3: calculate blood lipids

In step 3 you first need to select an Initial and a New diet. Then the webtool shows you the average changes in blood lipids when a group of volunteers changes from diet Initial to diet New. You have the following options:

• Enter blood lipid values for the Initial diet. The webtool then displays the values on the New diet.
• Switch diets
• Switch from mmol/L to mg/dL

References

• Saturated, mono- and polyunsaturated fatty acids:
  Mensink RP, Zock PL, Kester ADM, Katan MB: Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials. Am J Clin Nutr 2003; 77: 1146-1155.
• Trans fatty acids:
  Mozaffarian D, Katan MB, Ascherio A, Stampfer MJ, Willett WC: Trans fatty acids and cardiovascular disease. New Engl J Med 2006; 354: 1601-1613.
• Fish fatty acids:
  Harris WS: n-3 fatty acids and serum lipoproteins: human studies. Am J Clin Nutr 1997; 65: 1645S-1654S.
• Dietary cholesterol:
  Weggemans RM, Zock PL, Katan MB: Dietary cholesterol from eggs increases the ratio of total cholesterol to high- density lipoprotein cholesterol in humans: a meta-analysis. Am J Clin Nutr 2001; 73: 885-891. Dietary protein (tentative data only!): Katan MB: Alternatives to low-fat diets. Am J Clin Nutr 2006; 83(5): 989-990