Histidine
Isoleucine
Leucine
Lysine
Methionine plus cystine
Phenylalanine plus tyrosine
Threonine
Tryptophan
Valine
Examples in patient care:
Patients are typically given a daily high protein gram intake goal to assist in healing and repair after surgery. Daily intake goals may range anywhere from 60 to 80 g for women and 80–100 g for men.
This may vary by the individual if there are any compromising health concerns related to a high-protein diet (such as with kidney disease).
Protein recommendations may range from 1.2 to 1.5 g per kilogram of a patient’s ideal body weight down to .8–1 g per kilogram of a patient’s ideal body weight.
Higher protein diets in patients after bariatric surgery are recommended to promote healing for 1–3 months after surgery. After this time, patients’ needs should be assessed via routine lab work, if possible lean body mass analysis, and patient interview to determine if it is still medically necessary to maintain a high-protein diet.
If a patient is unable to maintain their high-protein diet, they are at greater risk for decreased rate of healing, fatigue, lethargy, protein-calorie malnutrition, and hair loss.
A good bariatric team should provide the patient with information, resources, and tips on how to accurately keep track of protein intake. It is the patient’s responsibility after their procedure to make an effort to meet their dietary goals.
Before and after surgery, patients are typically instructed to navigate the market for protein supplements to increase protein intake while still using smaller portion sizes. They are recommended to use these protein supplements in shakes and to add them into foods such as yogurts, puddings, or hot cereal.
It is important for patients to find powders that are complete proteins (including all amino acids), <5 g of sugar per serving and somewhere between 15 and 30 g of protein per serving for optimum absorption [2]. The most popular varieties are whey protein isolate and plant-based protein powders (such as blends of pea, brown rice, and hemp). These are best tolerated, easy to find over the counter and are both popular and nutrient dense sources of complete protein to prepare for, and to heal after surgery.
If a patient is not amendable to using a protein supplement to increase their intake, they typically use alternative methods of increasing protein intake, such as adding things like nonfat dried milk powder, egg whites, silken tofu, plain Greek yogurt, and other low-fat dairy foods into their diet (Table 31.2).
Table 31.2
Popular dietary sources of lean protein (per ounce)
Tuna (canned): 7 g
Chicken (cooked): 4 g
Greek yogurt (nonfat): 3 g
Tofu (extra firm): 3 g
Lentils (cooked): 3 g
A caution on exceeding protein gram recommendations: patients who exceed recommendations on daily protein intake may be at increased risk for constipation, stress on the kidney or other organs, dehydration, hypertension, and high LDL cholesterol. Current research does not support any evidence that excessive protein intake is beneficial for weight loss or weight loss maintenance.
31.1.2 Fat
Energy
9 kcal/g
Function
Fats/lipids constitute 34 % of the energy in the human diet [1]. Stored in adipose cells, humans are able to survive for weeks and months if there is little or no food available. The fat not used effectively is called structural fat which pads organs and nerves in position to protect them against injury, protects bones from mechanical pressure, and even insulates the body. Fat in the diet is essential for digestion and absorption of fat-soluble vitamins and phytochemicals.
Components
Fatty Acids: simple lipids (neutral fats + waxes)
Saturated fatty acid: no double bonds between carbons
Monounsaturated fatty acids: one double bond
Polyunsaturated fatty acids: two or more double bonds
Essential Fatty Acids: must be consumed by the diet and cannot be synthesized in the human body alone. Optimum ratio is 2:1–3:1 for brain health
Omega-6: arachidonic acid (ALA) – flaxseed, canola, soybean oils, and some green leafy vegetables
Omega-3: eicosapentaenoic acid (EPA) – cod liver oil, mackerel, salmon, sardines, and sea vegetables
Compound lipids: phospholipids, glycolipids, and lipoproteins
Miscellaneous lipids: sterols(e.g, cholesterol, vitamin D, bile salts, and vitamins A, E, and K)
Examples in patient care:
Patients are typically advised to be cautious of fat intake, especially those who have undergone a malabsorptive procedure such as the gastric bypass or BPD-DS due to increased risk of dumping syndrome. Patients who have had their gallbladders removed may also experience dumping syndrome after consuming foods high in concentrated fat.
Foods high in fat not well tolerated after surgery are pastries or sweets; high-fat dairy products such as cheese, heavy cream, butter, and sour cream; high-fat meat such as red meat or processed red meats like hot dogs, luncheon meat, sausage, or pepperoni; high volume of any type oil at one serving (such as in salad dressings or foods sautéed in excess oil or creamy/rich soups); and fried foods.
31.1.3 Carbohydrates
Energy
5 g/kg
Function
Carbohydrates are used primarily to maintain blood glucose concentrations between meals. To ensure readily available supply, all cells store carbohydrates in the easily metabolized glycogen polymer. These are manufactured by plants and are a major source of energy in the diet comprising around half of total calories. Many larger molecules of carbohydrates are not digestible and classified as dietary fiber.
Components
Monosaccharides (glucose, dextrose, fructose, galactose)
Disaccharides (sucrose [table sugar], lactose [milk sugar], maltose [malt sugar], oligosaccharides)
Polysaccharides (amylose, dextrins)
Dietary fiber and functional fiber
Examples in patient care:
It is important for patients after weight loss surgery to continue choosing healthy sources of carbohydrates in their diet. Postoperative patients have difficulty tolerating white bread, rice, potatoes, and pasta. Most patients will again be able to include these foods in their diet after some time (typically <3 months).
High-fiber carbohydrates should be encouraged (4+ grams per serving) including packaged grains, vegetables, non-starchy vegetables prepared without excess oils or fats, fruits, and some dairy foods.
Foods not recommended for weight loss success are white processed sugar, sweets/candy, sweet baked goods, or sugar-sweetened beverages.
Patients who have undergone a malabsorptive procedure (Roux-en-Y gastric bypass or biliopancreatic diversion with duodenal switch) are subject to dumping syndrome. Dumping syndrome is an uncomfortable sensation causing sweating, uncomfortableness, and ultimately rapid digestion of the food from the duodenum to the end of the GI tract leading to urgent diarrhea. This may occur 15–30 min after eating a triggering food or even upward to 1–4 h. This negative reinforcement is often why patients avoid these foods after their weight loss surgery. Foods which are high in concentrated sweets are more likely to trigger this reaction in patients after this surgery for <5 years.
Fiber
Dietary fiber: intact plant components that are not digestible by gastrointestinal enzymes
Functional fiber: nondigestible carbohydrates that have been extracted or manufactured from plants
Both have been shown to have beneficial physiologic functions in the GI tract and in reducing risk of certain disease states and should be encouraged in a healthy diet to promote weight loss maintenance, healthy cholesterol, and blood pressure.
There is currently evidence-based research available to support a high-fiber diet in the support of weight loss and weight loss maintenance.
For every 1000 cal, patients are encouraged to take in <14 g of fiber per day. The recommendation for fiber by the American Heart Association is <25–35 g daily for a 2000 cal diet.
Patients who do not consume adequate amount of carbohydrate in their diet may be at risk to: fatigue, constipation, slow weight loss, difficulty feeling full, and lethargy.
31.2 Micronutrients
31.2.1 Vitamins
Definition
Organic compounds (or class of compounds) distinct from fats, carbohydrates, and proteins. Natural components of foods; usually present in minute amounts. Not synthesized by the body in amounts adequate to meet normal physiologic needs. Specific deficiency syndrome is a result of absence or insufficiency.
