Consider these pre-operative nutritional guidelines to be not a temporary pre-op diet but your new permanent lifestyle as it is a well-balanced sustainable diet. Start this journey with the right mindset. These guidelines should become your permanent diet after surgery as well, once your stomach is healed, this will guarantee not only successful weight loss but will prevent weight regain in the long run.

Understanding the reasoning behind the rules, makes it easier to follow them. There are several main reasons why you are required to follow pre-operatory diet before having weight loss surgery.

Balance hormonal system

Pre-op diet helps to control complicated hormone systems responsible for causing obesity (hormones are more important than calories, one of such hormones is insulin). When we eat sugar, our pancreas produces one of the most important metabolism hormones – insulin that converts sugar into energy (or fat, when do not use all the produced energy). When we eat too much sugar regularly, insulin levels become elevated, which leads to insulin resistance. That in turn works just like a drug addiction: our body becomes less sensitive to the same amount of insulin; thus, pancreas produces more and more of it to achieve the needed effect; however, when we have more insulin in our blood than sugar, our body tells us to eat some sugar to even out the balance (this is what causes sugar cravings, hunger attacks). And as soon as we eat sugar, our body produces even more insulin increasing this addiction. The cycle goes on.

Similar process takes place in our brain: sugar triggers the release of dopamine hormone into the same area of the brain that responds to heroin and cocaine. Eating sugar regularly changes your brain so that it becomes tolerant to the sugar, causing you to require more to get the same effect. Sugar has also been shown to cause the release of endogenous opioids in the brain, which leads to a rush similar to that experienced when a person injects heroin. All of this leads to a vicious cycle of cravings and needing more sugar to feel good.

In the meantime, all the excess sugar is being stored as fat, slowing down your metabolism, and promoting comorbidities such as heart disease, dementia, and cancer to name a few. This is a condition known as pre-diabetes. It is also called metabolic syndrome, insulin resistance, and syndrome X.

The key to weight loss, then, becomes focusing on foods that normalize blood sugar and lower insulin levels. If you eat the same number of calories from broccoli rather than cookies, you will lose weight. If you eat food that spikes your insulin level, you will gain weight. If you eat food that reduces your insulin level, you will lose weight. This is true even if the food contains exactly the same number of calories or grams of protein, fat, carbohydrates, and fiber.

For more information go to:

• The insulin – Weight Gain Connection
• Sugar Addiction Explained By Dr. Robert H Lustig
• Insulin or Calories: What’s Behind Weight Loss?
• Time to Act on Obesity
• Is a Calorie a Calorie? Processed Food, Experiment Gone Wrong
• Why is a Calorie Not a Calorie (with Spanish Subtitles)

Shrink enlarged fatty liver

Enlarged liver is a consequence of being overweight (also known as fatty liver disease). Following this diet causes the liver ‘shrink’ in size and softens it, making it easier to move during surgery. During laparoscopic bariatric surgery, the liver has to be lifted out of the way to access the stomach lying beneath it. If the liver is heavy, fatty and immobile, it is harder for the surgeon to see and gain access to the stomach underneath. This could be a reason for the surgeon to make additional incisions or even cancel a surgery and allow a patient more time to follow the diet to shrink the liver, or changing to open surgery. Open surgery means a larger abdominal scar, which results in longer recovery and increased risks, and of course additional surgery costs. To reduce the size of the liver, it is necessary to follow a diet that is low in carbohydrate, low in fat and moderate in protein.

Mental, emotional, and physical preparation for the post-operatory stage

Consider the pre-op diet to be a training that helps your body and mind adjust to the new lifestyle that will follow the surgery. As part of this preparation, you may be going through unpleasant sugar detox symptoms and caffeine withdrawal. Sugar and caffeine withdrawal happen when we change our diet not gradually but abruptly, thus consuming less stimulants (such as carbs and caffeinated beverages), which causes headache, general weakness, tiredness, mood changes, etc. You may choose to make diet changes gradually, slowly reducing amount of sugar and caffeine in your diet to avoid unpleasant withdrawal symptoms (if you choose this option, allow an extra week or two for your pre-op diet), or you may choose a cold turkey method (making all the changes abruptly). Regardless which option you choose, you want to allow your body and mind enough time to get prepared for the surgery to reduce post-operatory tiredness and fatigue.

For more information go to:

• How to Beat Sugar Detox Symptoms and Feel Better Than Ever
• 8 Symptoms of Caffeine Withdrawal

Losing weight

Dr. Zavalza and Dr. Hernandez may have certain weight loss requirements for patients with BMI over 50 that will need to be met before surgery. For low and medium BMI patients (with BMI between 30 and 50) there is no specific number of pounds you need to lose during the pre-op diet, rather concentrate on acquiring healthy eating habits and complete the goals mentioned above. Do the very best you can!

For RNY, Mini Gastric Bypass or SADI-S patients with high BMI (BMI > 50) it is very important to burn as much internal (visceral) fat as possible (the unhealthiest fat that surrounds our internal organs). The surgeons will need to manipulate the small intestine in order to perform a bypass, and in order to do that, they will need to separate it from the surrounding fat tissue. All the visceral fat is penetrated by many blood vessels that will need to be cut, thus increasing blood loss during surgery, and scar tissue during the healing process. In certain cases, for patients with BMI over 60 – 65 Dr. Zavalza and Dr. Hernandez will advise to proceed with a gastric sleeve or will make such a decision during surgery, if performing a bypass becomes too risky due to the amount of internal fat and bleeding risks. This will be discussed with high BMI patients prior to surgery of course.
For patients with high BMI the liquid part of the pre-op diet may be increased from the standard 3 days to 7 – 14 days or more.

Special note for patients with diabetes

If you have diabetes and are treated with medication, you will need to adjust your insulin or medication while following this diet. Please contact your Diabetes Specialist Nurse/Practice Nurse/GP before starting the diet.

Understand satiety

Eat frequently (5-6 times a day) but do not overeat: stop once you feel full! Do not try to always finish everything on your plate. Our stomach and guts send a signal (through the satiety hormones) to our brain that we are full about 15-20 minutes after we start eating, once our body starts responding to glucose from food with elevated insulin levels in our blood. If you eat slowly, your brain will receive those signals before you finish your meal, thus allowing you to not overeat. Recommended reading: We Found Out if It Really Takes 20 Minutes to Feel Full

Hunger vs. Thirst

Have a glass of water when you think you feel hungry. The feelings of thirst and hunger are very similar (the same part of your brain is responsible for interpreting hunger and thirst signals, which can result in mixed signals). If you have a glass of water and still feel hungry, then you are really hungry. Otherwise, the feeling will go away. Learn more at Hunger vs thirst: know the difference

Practice thorough chewing

Do not “inhale” food. Put your fork down between the bites. Enjoy chewing and tasting food in your mouth, pay attention to what you are eating and do not get distracted by TV or cell phone. Focus on your meal. These habits will be essential during the post-op stage.

Do not skip meals

Skipping a meal means you will be so hungry at the next meal that you are likely to overeat. Besides skipping meals can lead to a slowdown of your metabolism, meaning you’ll burn fewer calories.

When you blow your diet, do not give up

Do not wait until next day, or Monday or next month to go back to the right course. Resume your healthy diet with the very next meal. Every meal matters, if you had a piece of cake at a family gathering for lunch, get back on track at dinner.

All calories are not the same

Do not be obsessed with counting calories, because 100 calories coming from soda or chips are not the same as 100 calories coming from broccoli or almonds. Focus on healthy food choices and portion control (as will be explained further). What we eat is more important than how much we eat. Recommended additional reading: Why Is a Calorie Not a Calorie (with Spanish subtitles)

No drinking while eating

Stop drinking 30 minutes before you eat and do not drink again until 30 minutes after you eat. This will be a requirement following your surgical procedure and needs to become a lifetime habit. Think about your stomach as a colander (strainer), or a funnel. If you only put liquid in the colander/funnel it’s going to go straight through, but if you only put solid/soft food in that colander, it will drain through slowly. If you end up mixing water with the food, it thins it, allowing the food to go through the colander/funnel faster (or your stomach faster). By doing this, you won’t feel as full, allowing you to eat more during your meals and you’ll become hungry sooner, which all equates to consuming more food and more calories throughout the day. And after surgery you will want to fill up your limited stomach space with protein and nutritious food first, and drink later, thus, developing this habit now will become very useful in the future. Learn more at WLS – No Drinking With Meals!

Drink at least 2 L (or 64 oz.) of water a day

If you drink a lot of water you might lack potassium, which might cause leg or toes cramps (especially after work outs). To maintain proper levels of potassium, take Potassium Chloride 500 mg a day in pills (if needed), or add foods rich in potassium to your diet (example: spinach, tomatoes, broccoli, Brussel sprouts, champignon mushrooms, pickles or pickle juice, avocadoes, and apricots. Also, certain proteins like salmon, turkey, beef, and yogurt are rich in potassium).

Avoid artificial sweeteners

It goes without saying that added sugar is to be avoided, however, artificial sweeteners should also be avoided as much as possible. Extreme and unnatural sweetness encourages sugar cravings and sugar dependence. Non-nutritive sweeteners are far more potent than table sugar and high-fructose corn syrup. A miniscule amount produces a sweet taste comparable to that of sugar, without comparable calories. Overstimulation of sugar receptors from frequent use of these hyper-intense sweeteners may limit tolerance for more complex tastes. That means people who routinely use artificial sweeteners may start to find less intensely sweet foods, such as fruit, less appealing and unsweet foods, such as vegetables, downright unpalatable. Also keep in mind that artificial sweeteners (especially when used after surgery) often cause stomachache, diarrhea, and gas. Recommended reading: Artificial sweeteners: sugar-free, but at what cost? and Can “Diet” Make You Fat? The Truth About Artificial Sweeteners

Cook your own food. Learn meal prepping.

Avoid all types of fast food, even if seems to be a healthy salad or other type of healthy food, they often contain added sugar (especially premade salad dressings), taste enhancing chemicals and trans fats. Clean up your refrigerator and pantry, remove all bad foods to avoid unnecessary temptation. Think ahead what you are going to have for breakfast, lunch, and dinner and shop and cook accordingly. If possible, always bring your own lunch box to work with healthy foods. Use your own thermos with hot coffee or tea to avoid temptation to buy a beverage loaded with sugar and cream. For more useful tips go to Mastering Meal Prepping.

Avoid liquid meal substitutes

Always give preference to low-processed or non-processed food. Solid protein derived from such sources as eggs, poultry, lean meat, low-fat cheese, fish, and seafood, mushrooms, etc., will satisfy you much more than any type of liquid meal substitutes or protein shakes. You will have enough time to get tired of shakes during the 3-day liquid pre-op diet stage as well as during the first 3 weeks of the post-op diet when you will have no other choice but to stick to fluids. Enjoy solid food while you can, it will remain in your stomach longer to get digested and will provide the feeling of fulness much longer than liquid meals. Learn more at Pre-Op Diet: Liquid Meal Substitutes & Protein Shakes, Yea or Nay?

Use the rule of palm to measure your food portions easily without any scales, cups, grams, ounces, etc. No need to count calories either, simply follow this rule.

Your palm determines your protein portions.

Your fist determines your veggie portions.

Your cupped hand determines your carb/fruit portions.

Your thumb determines your fat (nuts/seeds/cheese) portions.

We do not recommend chewing gum before or after sugrery as it stimultaes stomach acid production and could cause worse acid relfux after surgery as well as make us feel more hungry.

Breakfast

Option 1: Omelet (1 whole egg + 1 egg white, handful of spinach, tablespoon of chopped onions, olive oil, salt and pepper in moderation)
Option 2: Scrambled eggs (1 whole egg + 1 egg white, any fresh mushrooms 4-6 pieces, tablespoon of chopped onions, olive oil, salt and pepper in moderation)

Snack

Option 1: Small Greek yogurt (sugar-free) with 1 handful of fresh blueberries
Option 2: Lettuce wrap with two thin slices of turkey breast

Lunch

Option 1: Mixed greens salad (olive oil, salt, pepper, lemon juice for dressing), grilled chicken breast (1/2 of breast or equal to palm size)
Option 2: Tomato and cucumber salad with shrimp, chickpeas, or green peas

Snack

Option 1: 10-15 almonds, ½ large apple (or 1 small apple)
Option 2: Two small pieces of cheese, any fruit/fresh berries (1 handful)

Dinner

Option 1: Sautéed broccoli (use onions and garlic, lemon juice, salt and pepper, other spices to add flavor), fried/baked/grilled tilapia (1/2 filet or portion equal to palm size)
Option 2: Grilled beef steak (choose lean meat, palm size portion, no heavy sauce), a handful of drilled asparagus

Snack (if necessary)

Option 1: A slice of cheese (finger size portion) with 1 mandarin
Option 2: Two table spoons of hummus with 1 celery stick and 4-5 baby carrots

Consider our featured bariatric-friendly recipes:

Cloud Bread

Zucchini Tuna Patties

Green Omelette Recipe

Veggie Egg White Bites

Shrimp Lettuce Tacos

Chickpea Salad Recipe

Chocolate Protein Pancakes

Frozen Blueberry Yogurt Bars

Visit Pre-Op Instructions for a Meal Plan & “liquid” recipes for the Liquid Pre-Op Diet Stage.