Evolution as a food preference

Eating behaviours are adaptive that have evolved over time to help humans survive. 

The human evolutionary line split from the great apes about 2 million years ago. EEA - Environment of evolutionary adaptation.

Human's rapidly because omnivores.

We have evolved a digestive system suited to breaking down these foodstuffs into nutrients we need.

We have a preference for sweet, meat and salt. Neophobia and taste averison. 

Preference for sweet

• Sweet food triggers the release of the pleasure-inducing brain chemical dopamine which acts as a reinforce. 
• Sweetness means fruit is ripe.
• Fruits are high in sugar/ carbs - energy/ calories for the brain. 
• Non-toxic.

Research for sweet;

• Desor and Steiner - using choice preferences and facial expressions found neonates prefer sweet foods to bitter ones, implying it is innate.
• Read and McDaniel - point out that genes alone are not thought to be responsible for the variations in sweetness reception in humans. The protein hormone leptin has an inhibitory effect on taste reception skills, reducing the amount of sweetness signals transmitted to the brain. During times of food scarcity, less leptin is produced, making sweet less attractive.

Preference for salt

• Having salt in our diet is essential for survival.
• Without salt we would dehydrate and die.
• Important for the function or neural and muscle activity.
• Too much salt can lead to high BP and associated health risks.
• Deprivation causes cravings/
• grazing animals seek out salt to complement their salt poor diets, unlike carnivores like lions that get sufficient salt from raw meat.

Research for salt:

• Denton - found that innate preference for salt is found in many, varying animal species, which suggests that the preference has a survival value and is determmined by evolution. 
• Highland deer eating salt in winter from roads.
• Although a preference for salt was adaptive in the EEA, it now causes problems for people who consume…