Foods to avoid and to eat


This blog provides free information about the healthy food pyramid, not intended as a medical consult. Please seek appropriate advice from an accredited practising dietician with specialised interest in bariatric surgery, for an individual assessment, personalised advice, individual tailored management and diet plan.

Although this blog concentrates on the diet aspects for surgical patients, it is recommended for most people in our Western society whether they have bariatric surgery or not.

Food pyramid post-bariatric surgery

Bariatric surgery is most effective and durable when it is combined with post op diet changes. This involved food portion control, good food choices and proper eating habits, with the aim on reduction of consumption of foods with high caloric contents and substitute them with healthy foods that promote a more active metabolism.

Weight loss success in the long term (beyond 2 to 5 years) is only possible with behavior modifications, a change in eating habits and a change in the level of physical activities or exercise. The secondary aim is long-term nutritional care and maintaining a healthy physiology (preserve lean body mass, active metabolic rate and sufficient bone mineral density).

The bariatric surgery food pyramid is slightly different to the traditional food pyramid models. It aims to promote good nutrition and at the same time is design to limit caloric intake, in order to provide the recommended daily intake of macro and micronutrients as well as to prevent the nutritional deficiencies that may be the result of the weight loss surgery.

Please search Google for images on the bariatric food pyramid.

The daily recommended intake from the food pyramid is:

  • Adequate vitamin and mineral supplements, plenty of water and decaffeinated beverages.
  • 4 to 6 serves of lean meat, dairy product with little or no fat (such as low fat cheese, milk, low fat yoghurts), legumes (beans) and eggs.
  • 2 to 3 serves of vegetable, eggs, olive oil, fruits that is low on sugar content.
  • 2 serves of carbs (cereals, potatoes).
  • Avoid saturated or trans fat, food with cholesterol or high sugar contents, alcoholic or sweet carbonated beverages.

Issues that may arise after bariatric surgery

The problems that can be encountered after bariatric surgery may be due to food intolerance, early or late dumping syndrome, small bowel malabsorption (due to the bypassed segment) or other physiological changes in the gastro-intestinal system.

Typically after a gastric bypass operation, lifelong supplements for vitamins (B1, B12, A, D and E) and trace minerals (iron, folic acid, calcium, zinc, magnesium, chromium and selenium) are necessary in order to prevent micronutrient deficiencies.

Foods to avoid

There are research studies that suggest that some patients are eating the wrong food groups after bariatric surgery despite being educated properly by trained dieticians and medical practitioners. It is found that most still have too much carbs and inadequate protein, dairy products, vegetables or vegetable oils.

The aim of the food pyramid is to avoid:

  • Inadequate protein intake, which may lead to loss of lean body mass, loss of an active metabolic rate (inadequate weight loss) and poor body contour.
  • Inadequate dairy products, which may result in calcium and vitamin D deficiency, consequently poor immune function, reduced bone mineral density and secondary hyperparathyroidism, with a risk of post menopausal osteoporosis.
  • Inadequate fruit and vegetable intake, which may result in folic acid deficiency.
  • Vegetable oils (preferably olive oil) is recommended to be added to the diet in order to provide fat soluble vitamins, essential fatty acids and it may also increase satiety.
  • Sugar (high glycemic or GI index) rich foods (such as chocolates, cakes, ice-cream, lollies) are to be avoided because it will inhibit weight loss and often causes early dumping because of its osmotic rich properties.
  • Carbs (bread, pasta, rice) are to be avoided because of its high glycemic load, which will cause weight regain and carbs are often the cause for food intolerance (dumping). Food intolerance (vomiting or diarrhea) is often related to fatty foods or concentrated sweets.
  • Alcohol beverages (a high caloric content drink) are to be avoided because it will cause weight regain, often increases the risk for vitamin and mineral deficiencies, reduces bone mineral content, not to mention the adverse health consequences of alcohol consumption).
  • Fatty meals (sausage, pates, fried food, oily meat, cheese) should be strictly avoided because of its high caloric content contributing to inadequate weight loss and weight regain in the long term besides increasing cardio-vascular risk factors.

Studies have pointed to failure of dietary changes as the major contributing factor to inadequate weight loss and weight regain, with the return to high consumption of carbs, sugars and fats.

Hence bariatric surgery is really about long term sustained weight loss coupled with improved diet and nutrition, increasing exercise or in other words a complete lifestyle change.

The key points are:

  • Good food portion size (restrict calorie intake)
  • Good food choices (improve quality of meals and nutrition)
  • Good eating habits (avoid binge eating or eating disorders)
  • Maintain regular physical activities or exercise (healthy metabolic rate and optimize body physiology)



Superfoods are increasingly being emphasized by nutritionist and often mentioned in the media as beneficial and desirable.

Although superfoods are yet to be conclusively proven for treating or preventing certain diseases, they do provide generous amounts of vitamins, minerals and essential fatty acids and are better than ordinary foods.

But rather than just eating superfoods dieticians emphasized that it be incorporated into a balance meal. It is better to aim for a minimum of five portions of whole fruits and vegetables per day. Play back in your mind the wise words from your mum or grandmother to “eat more fruit, vegetables and wholegrains” and avoid processed or preserved foods as well as food high in animal saturated fat or trans fat.

The main health benefits of superfoods include:

  • Help to regulate metabolism and reduce body fat
  • Protect the vital organs from toxins
  • Lower cholesterol and blood pressure
  • Prevent or reduce inflammation in the body
  • Prevent cardiovascular and cancer risk
  • Promote digestive health

No specific lists of superfood exist and no single food group has all the above mention qualities. But we are being told that certain foods are definitely beneficial and should be included in our daily intake, which includes:

  • Oily fish (salmon, sardines) – rich in omega 3 fatty acids
  • Tomatoes – high in lycopene
  • Olive oil – rich in antioxidants and good fats
  • Brazil nuts – high in selenium
  • Berries – high in antioxidants
  • Broccoli – high in antioxidants and folate
  • Beans – high in fibre and antioxidants
  • Natural yoghurt – contains the good bacteria for our gut
  • Soy – rich in protein and high in fibre
  • Tea, black or green – high in antioxidants

In general antioxidants help to reduce cardiovascular risk factors and cancer by protecting the body against free radicals. Antioxidants include vitamins A, C, E, beta-carotene, lycopene and minerals such as zinc, selenium and copper.

Probiotics contain the micro-organisms that are naturally found in the human digestive tract, to help improve the balance of healthy bacteria in the gut. Probiotics have been shown to help reduce digestive symptoms such as constipation and bloating, help restore gut flora depleted after oral antibiotics and help restore the bacteria required for optimal nutrient absorption. Research suggests a link between healthy GI tract and immune function, which support the inclusion of probiotics to our daily food regime.


Most vegetables are a good source of fiber, vitamins and anti-oxidants.

Leafy vegetables have minimal or no saturated fat and the best way to cook them is simply is simply steaming without adding oils or dressings (to avoid calories).


It is a good source of vitamin A, C, K, folate, thiamine and riboflavin as well as minerals such as manganese, copper and potassium.

Asparagus is recommended as a source of folate, particularly important during pregnancy to prevent fetal neural tube defects.

Recently it was found to contain fructo-oligosaccharides, a soluble fiber which may be beneficial in lowering blood cholesterol and triglycerides.

Asparagus shoots may be cooked by steaming or roasting, which gives it an excellent flavor and texture.

Chinese broccoli or kale:

The green leafy vegetable and stem has a sweet flavor and is used very much in Asian cuisine, hence its name.

This is a good source of vitamin A, C, K, folate, thiamine, riboflavin, fiber, calcium, manganese and potassium.

Globe artichoke:

Artichoke is very popular in French, Italian and Spanish cuisine, is cooked until it is tender and delicious to eat.

This is a good source of fiber, vitamin C, K, folate, iron, potassium, riboflavin, niacin and anti-oxidant lutein.

It has been found to contain cynarin, which may help to lower cholesterol.


Spinach provides an excellent source of vitamin A and K as well as good source of vitamins B6, C, E, folate, thiamine, riboflavin, manganese, magnesium, iron, calcium, potassium, copper, zinc, omega 3 fatty acids and anti-oxidants.

Spinach tastes excellent when it is lightly sautéed with olive oil and eaten as the main ingredient, also used a lot to compliment French or Indian dishes.


Pumpkin (squash) is commonly used in soups, they can also be eaten after being roasted or mashed.

The orange colour indicates that it is a good source of beta carotene and carotenoid anti-oxidants (alpha carotene and beta crypto xanthin), helpful to prevent cardiovascular disease and unknown immune-modulating activities for cancer prevention.

Squash are good sources of vitamin A, C and fiber.


Wakame is an edible seaweed, cultivated in Tasmania for exports.

It is an important ingredient in Japanese Miso soup and is highly nutritious.

It is a good source of omega 3 fatty acids, folate, manganese, calcium and magnesium as well as anti-oxidants such as fucoidan and carotenoid fucoxanthin, which may be useful against obesity and diabetes.



Common mushrooms found in Australian supermarkets include white, brown, field and oyster mushrooms.

Common Asian/Japanese mushrooms include Shiitake and Enoki, all of which are very tasty.

Mushrooms are the fruits of fungi and can be eaten as the main dish.

They are an excellent source of riboflavin, niacin, pantothenic acid, selenium, copper, potassium as well as thiamine, zinc and manganese.

A lot is still unknown about mushrooms or their special bioactive compound in terms of disease prevention or its anti-cancer activities.


Nuts contain essential micronutrients such as zinc, copper, manganese, selenium and magnesium.

Brazil nuts:

Brazil nuts have exceptionally high selenium content, crucial for the thyroid gland and is a good antioxidant. Brazil nuts are also extremely rich in vitamin E, copper, magnesium and zinc. While a diet rich in selenium is related to a reduced risk for some types of cancer (prostate and gastric).

However Brazil nuts are higher in fat compare to other nuts, with 20g of total fat per 30g serve, hence the recommendation is to consume them in moderation.


A serve of 30g (30 pistachios), contains 15g of fat, 10g carbohydrates, 7g of protein and almost 3g of fibre, making them a nutritionally balanced snack or a good addition to salads. Pistachios are also a source of the powerful antioxidant resveratrol, which is known to reduce inflammation and prevent damage to the blood vessels. They are rich in vitamin B6, vitamin K, potassium and copper.


Amongst the nuts the walnut has one of the highest concentrations of the plant source of omega 3 fat, alpha-linolenic acid (ALA), making it an extremely good choice for people with heart disease or type 2 diabetes.

Walnuts are also a good source of vitamin E and the key nutrients zinc, iron, manganese, vitamin B6 and folate. Studies have shown that eating 30g (10 walnuts) daily can help lower blood cholesterol levels.


Cashews are slightly sweeter than some of the other nuts and can be added to salads, stir fries or made into a tasty paste as an alternative to butter. Cashews have a similar nutrient profile to that of pistachios but with less fibre per serve and are best consumed in unsalted varieties.

Particularly rich in vitamin K (which is linked to lowering blood pressure), copper, magnesium and folate along with the antioxidant squalene known to have a range of anti-cancer functions in the body. 20 nuts amount to 730 kilojoules, 15g of fat and 5g of protein and should be consumed in moderation.


Almonds are often considered high in protein with almost 7g of protein per 30g serve, similar to walnuts. Almonds are also full of fibre (more than 3g per 30g serve), along with good amounts of vitamin E, magnesium, calcium, iron and zinc.

Almonds also have relatively high levels of antioxidants and some research has linked their consumption to reduced insulin secretion in the body and better blood glucose control. The dry roasted varieties are preferred and to avoid the varieties with added salt or sugar (honey cashews).

15-20 almonds have 15g of fat, much of which is monounsaturated fat. Again it should be consumed in moderation.





Fruits should be eaten fresh, without the addition of sugar, syrup, melted chocolate, ice creams, etc. to reduce the calorie content, to avoid the risk of obesity and diabetes.

Fresh fruits in general have very low calories and the common ones are listed below.

Not listed below are oranges, pears, papaya, apricots, plums, nectarine/peach, apple, pineapple, etc. all of which are recommended too.


Tomato is a fruit (not a vegetable) because it contains seeds.

Tomato is essential in Italian dishes but is also very popular amongst all cultures.

It is high in vitamin A, C, K as well as a good source for vitamin B6, folate, manganese, chromium, potassium and anti-oxidants such as beta carotene, lutein and zeaxanthin.

Recently lycopene that is found in tomato is useful in prevention against certain cancers (prostate and myeloma).


Mandarin is a good source of vitamin A, C, B6, thiamine, calcium, folate, magnesium and potassium as well as anti-oxidants (such as alpha carotene, beta carotene, cryptoxanthin, lutein, zeaxanthin) and flavonoids (tangeretin, nobilectin).

Fruits should be eaten raw or it may be added to salads (instead of meat) as a healthy alternative and to assist with weight loss.

Tangeretin has also been reported to be useful in fighting cardiovascular disease, reduce cholesterol and other diseases.


Lemons in general are used throughout the world although Australians are less familiar with some other varieties from China and India.

It is an excellent source of vitamin C, phytochemicals (phenols, essential oils) and anti-oxidants (such as limonin, limonene), which may have anti-cancer properties.

Instead of adding oils or mayonnaise to salads, try adding lemon juice as a healthier alternative.


Note avocado by itself has a very high total fat content.

It is an excellent source of vitamin B6, C, E, K, folate, pantothenic acid, riboflavin, niacin, magnesium, potassium, copper, manganese, thiamine, iron, phosphate and zinc.

It has anti-oxidants (carotenoids lutein, zeaxanthin) and fatty acids (alpha linolenic and oleic acids). The combination of carotenoids and vitamin E may have anti-cancer properties and it has been suggested that avocado is useful to prevent diabetes.

Avocado is popular with chicken or salmon sandwich.


Sweet cherries are an excellent source of vitamin C, potassium, copper and manganese as well as phytochemicals (anthocyanin, flavonoids).

Sour cherries are an excellent source of vitamin A, C, potassium, copper, manganese, anthocyanin, flavonoids and anti-oxidants (carotenoids).

Sour cherries have been found to be useful in fighting inflammation, cardiovascular disease and help to prevent metabolic syndrome.

Acai berry:

This berry come from palm tree, is trendy at the present time because of endorsement by some celebrities.

Acai berry juice and extracts are good sources of vitamin C, E, iron, potassium and anti-oxidant phenols.

Summary of foods to avoid:

Sugar and artificial sweeteners

The key message is to avoid sugar, refined starches and other artificial ingredients but not the natural fruits. Desserts (cakes, biscuits, chocolate, pastries, desserts and soft drinks) have extremely high calorie content with minimal nutritional value. Replacing sucrose or fructose (in fruits) with other added refined sugars like glucose or rice syrup may in fact provide more calories, have a higher glycemic index (GI). Besides foods with naturally occurring sugars are also important sources of fibre, vitamins and minerals, which are encouraged.

Saturated fats and trans fat

Most Australians consume food with too much saturated fat (full fat dairy, packaged foods using palm oil or coconut oil, or fried and fatty takeaway food).


Wheat contains fibre, folate, B-vitamins, iron, zinc, magnesium, protein and carbohydrates. The problem is eating too much refined wheat (portion size), usually in the form of snacks, cakes, biscuits and pizza, which are loaded with other sugar, fat or salt.

Cutting down on refined wheat products can help people lose weight and improve their overall diet. The wholegrains (including quinoa, oats, barley and brown rice) and whole grain bread is preferred to white bread.

Summary of foods to eat:

Lean protein: 
Omega-3-rich fish (salmon and sardines), steamed or fresh (sashimi) fish, prawns and scallops, omega-3 eggs, poultry (without the skin) and good quality lean meat. Avoid deep fried, BBQ or preserved chicken or meat.

Beans or legumes: They are a good source of protein, fibre, minerals and vitamins.

Slow-burning, low-GI vegetables: Steamed broccoli, asparagus, spinach, silverbeet, kale, cabbage, bok choy and cauliflower. Aim for six to seven serves a day.

Garlic and onions: They may help to lower cholesterol and blood pressure, contain antioxidants and anti-inflammatory properties.

Seaweed: Kombu, nori, hijiki and wakame are all extraordinarily high in minerals, protein and healing compounds.

Nuts: The best are almonds, walnuts, macadamias, hazelnuts and pecans. Try not to have more than 10 to 12 nuts once or twice a day.

Wholegrains: Up to half a cup a day of brown, black and red rice, quinoa, amaranth or buckwheat.

Berries: Blueberries, cherries, blackberries and raspberries are full of phytonutrients.

Apple, pears and stone fruit: They are a source of fibre. Limit to one to two serves a day and avoid preserved fruits in syrup or sweets/desserts.

Green tea: It may have antioxidant phytonutrients, anti-inflammatory and detoxifying properties.