Page 362 - Special Topic Session (STS) - Volume 4

STS1080 Karina G. et al.

2.2. Formalization of the Nutritional Plan
A nutritional plan contains the specification of the proportions of families
of foods to be taken during a certain period of time. A nutritional plan is
defined as the triplet = < , , > where,
• F = (π1, ..., πN) is a vector containing the recommended balance of food
families to be taken along a certain period of time.
• π ,{1:} is the proportion of food family recommended, such that

(∑ =1: π = 1), given a set of N foods families ℱ = { , … , } (i.e.,

1
fruits, proteins, etc.)
• = [ , ]is the period of time where the diet must be followed
0
• indicates the total quantity of food in Kcal to be intaken along the
whole diet.
The quantity is needed due to the fact that food proportions are
different for children, young or elderly people

2.3. Hard Nutritional Restrictions Management
The Personalized Menu Planner must deal with additional restrictions to
be satisfied by the final recommendation. According to health conditions and
medical reasons, nutritionists may impose some restrictions in the design of
the menu and Diet4you must preclude or force the proposal of restricted food
families in the menus of a certain person. For example, for diabetic patients,
sugars will be restricted, or refined flours might be mandatory, for persons
with cholesterol, saturated fats might be mandatory. In addition, known
allergies of the person can be managed as well by restricting the
corresponding foods (nuts, strawberries, fish...). Finally, strict cultural features
of the person, like avoiding meat for a vegetarian person, avoiding pork meat
for a Muslim, can be managed as well under the mechanism of hard
restrictions. Diet4You guarantees that the proposed menu will not include a
single dish containing restricted ingredients or food families. This strategy is
implemented by filtering the food database according to restriction and using
the food and dishes ontology and building the personalized menu over the
filtered database.

2.4. User Preferences
Diet4you can manage the user preferences as well, in an attempt to
increase adherence to diet. A user preference expresses that a person likes or
dislikes some kind of food. If a person dislikes fish or chicken, he can declare
in Preferences section and the system minimizes the probability of including
dishes that contain unpreferred ingredients for the final menu and maximizes
probability of using preferred ingredients. In this case there is no guarantee
that the disliked food is completely eliminated from the proposed menu, and
the nutritional prescription can force the person to accept some specific food

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