GI/GU: Nutrition

Nutrition is defined as the process of obtaining food and using it for maintenance, growth, and repair. It can be broken down into ingestion, or taking in food; digestion, or breaking it down into nutrients; absorption, or pulling those nutrients into the bloodstream; and, finally, metabolism, or turning these nutrients into energy.

This energy is calculated in units known as kilocalories, or simply calories. Nutrients found in food can be divided into two groups.

The first includes carbohydrates, proteins, and fat which provide energy; while the second group, including minerals, vitamins, and water, offers no energy but is still essential for normal body function.

Starting with carbohydrates which are found almost everywhere from fruits and vegetables to dairy and grains. They are one of the main sources of energy in the body, providing 4 calories per gram.

There are simple carbohydrates or sugars that the body can readily absorb and the most important of these is glucose.

Complex carbohydrates, or starches, take longer to break down and absorb. There are also dietary fibers which are found mostly in fruits, vegetables, legumes, bran and oats.

Fibers are carbohydrates that intestinal enzymes can’t break down at all, so they pass through the intestine undigested and ultimately end up as bulk matter in the stool.

In this way, they help increase stool weight and prevent constipation. Next, proteins can be found in many animal products, like dairy, meat, poultry, and eggs as well as plant-based products, like beans and peas, soy, nuts, and seeds.

Just like carbohydrates, each gram of protein provides 4 calories. At the same time, though, proteins can be broken down into amino acids which we largely use to make our own proteins as well as hormones and other molecules needed for the immune response or tissue repair.

Fats or lipids are found in oils, butter, avocados, and meats. They are a major source of energy, providing 9 calories per gram but also a critical component of cells and tissues.

They help absorb essential vitamins, known as fat-soluble vitamins, and can be converted into other molecules like prostaglandins which help cells communicate with one another.

Moving on to the next group of nutrients: minerals. These include calcium, phosphorus, iron, iodine, sodium, and potassium and have various roles in the body, like building strong teeth and bones, producing enzymes and hormones, and maintaining proper function of the heart, brain, and muscles.

Vitamins can be categorized as either water-soluble or fat-soluble. Water-soluble vitamins include vitamin C and B-complex vitamins which are readily absorbed into the circulation but aren’t stored anywhere.

This means any additional amount consumed can get easily excreted. On the other hand, fat-soluble vitamins include vitamins A, D, E, and K.

These are absorbed along with fat and are then stored in the body’s fatty tissue and liver for future use. But since they don’t dissolve in water, they can’t be easily excreted in the urine. So if you take too much, they could build up and become toxic.

Finally, water is essential for human life. About 80% of our water intake comes from drinking fluids; the other 20% comes from the food we eat.

It makes up for more than 50% of a person’s body weight, and it’s directly involved in every biochemical reaction in our body.

Water helps lubricate the pleural and pericardial cavities in the chest and the peritoneal cavity in the abdomen where internal organs touch and slide over one another.

It’s also needed in joints where it helps form the synovial fluid that keeps our bones from rubbing against one another.

Water is critical for digestion: The water in saliva moistens food when we chew, while gastric and intestinal juices are a fluid environment in which digestive enzymes break down our meals.

Water forms the bulk of blood which allows oxygen and nutrients to easily move around the body and plays a role in eliminating toxins from the body through urination and defecation.

Water also helps regulate body temperature: When we’re hot, like during a vigorous workout, the capillaries in our skin dilate and sweat glands produce more sweat to help dissipate heat.

A balanced diet is the one that supplies the body with an adequate quantity of the nutrients it requires to function properly.

This is essential for maintaining both physical and mental health, a healthy body weight, better sleep, and boosting the immune system.

It’s also essential for preventing various health conditions, such as obesity, heart disease, diabetes, some types of cancer, and bone diseases.

There are several ways to help someone keep a balanced diet, like reading the nutritional label on packaged food and referring to MyPlate which stresses the consumption of a wide variety of foods from all five major food groups: grains, fruits, vegetables, milk, and meat.

Now, there are many other factors that can affect what and when a person wants to eat, ranging from personal taste, hunger, and the ability to cook to budget issues and religious or cultural traits.

Now, in some facilities, a nurse carries out a dietary assessment, noting the client’s eating patterns and food likes and dislikes.

This is then used by a dietitian, meaning a nutrition specialist, to design a personalized, healthy, and sustainable diet plan.