Sandy McFadden

This is a very simple plugin which requires almost no configuration.
All you need to do is go to the Appearence then Widgets area in the Admin Dashboard. 
Once you are there drag the BMI Calculator widget onto the widget area you would like it added to.
The only two settings are the title and the color. The color is the hex color you would like the results background to be.
A lot of the code was adapted from 
<a href="http://codereview.stackexchange.com/questions/21581/calculating-body-mass-index-bmi" title="Inspiration Code" rel="nofollow ugc">Stack Exchange Thread</a>

Healthy BMI Calculator

Adds a shortcode and widget that will display a simple BMI Calculator on your site. Works with both metric and US style measurements.

granludo

Given a recipe calculates Nutrition Facts and shows a Nutrition Facts Label 
Our WordPress plugin allows you to display a label with the 
nutritional values of your recipes in the entries and pages of your blog.
The information includes data in kilocalories, carbohydrates, sugars, 
fats, proteins, cholesterol, vitamins and minerals. In addition, give the 
Recommended Daily Amount (CDR) of each nutrient contained in 100 grams of recipe *.
Your nutritional information label in just two steps
Enter the ingredients of your recipe. As you type the name of each ingredient a list 
of suggestions is displayed. 
To finish you just insert the shortcode indicated inside the text of your entry or page. 
Nutrition information is automatically calculated and displayed on a perfectly formatted label.

Info Nutricional

Calculates and display a Nutrition Facts label for a recipe. Nutrition values are calculated from the ingredients and quantities in the recipe.

Healthy BMI Calculator vs Info Nutricional