I am one year living in New Zealand and I’m delighted to be back into the flow of nutrition! I was previously working as a medical writer in Singapore and I am now working as a tutor in a nutrition college in Auckland.
I really love to share and discuss what I’ve learnt from my masters in nutrition, training and work as a dietitian and of course my own personal experiences! I am always trying to find simple ways of improving my diet and obtaining better overall health and fitness. A lot of my work involves developing lecture content and my goal is to share some of this information along with my own experiences with you! There is so much contradictory information available online and it frustrates me when the media zones in on snippets from research articles without actually showing the true context of what the findings actually really mean! Most of us don’t have time to read full research articles and instead rely on these random and often contradictory pieces of info.
It’s been awhile since I wrote a blog so I’m going to start with the most common question I get asked and it’s about fat..!
More fat less carbs..?
This week I am looking at fat and carbohydrate (carb) balance. For years it has been recommended to follow a low fat diet because fats have a greater calorie density than carbs or protein and because some fats eaten in large amounts are considered unhealthy. There is now a shift towards increasing fat and lowering carbs in the diet. Below I outline some of the reasons why.
Essential fatty acids
Fats provide essential fatty acids; that is omega 3 and omega 6. We cannot make these two families of polyunsaturated fatty acids in our body and we rely on food sources. These fatty acids are important for the structure and fluidity of cell membranes that surround every cell in your body. So if you want supple skin you need a good supply of these fats! They are also important for hormone and neurotransmitter function, and they even affect how genes are expressed! 1
Omega 3 and omega 6 are commonly found in the same types of foods but the ratios of each can vary. Good sources of omega 3 include oily fish such as salmon and mackerel, eggs, dark green veg and nuts and seeds such as linseeds, chia, and pumpkin seeds, and walnuts. There are more widespread sources of omega 6 and it is commonly found in meat and processed foods such as cakes, biscuits, and fried food. This is because the main oils used (vegetable oils such as sunflower and corn oil) in these processed foods are high in omega 6 but lack omega 3.
The other important function of these essential fatty acids is in relation to inflammation. Omega 3 helps to dampen down inflammation, whereas excess omega 6 can enhance inflammation. When your body is in a pro-inflammatory state you are more prone to free radical damage and disease risk. At the moment most of us eat a diet that has a 15:1 ratio in favour of omega 6; whereas it should be a ratio of around 4:1.2 A high carb diet is also considered to cause more inflammation in the body.3
Omega 3 foods also supply EPA and DHA, which are essential for brain and cognitive function. So basically we do need to eat fat and more specifically we should be eating more nuts, seeds, and if you are not vegetarian/vegan oily fish!
Fat soluble vitamins A, D, E and K are found in foods that contain fat. Vitamin A and E are key antioxidants in the body. They help to protect our cells from free radicals. Free radicals are produced in our body all the time but if we have enough antioxidants they are neutralised and cause no harm. If you don’t have enough vitamin E in the diet then every cell in your body becomes vulnerable and can be badly damaged by these free radicals. Key sources of vitamin E are vegetable, nut and seed oils. If you buy highly processed oils then vitamin E and other nutrients are removed, and this makes these oils more susceptible to damage by oxygen in the air. That’s one of the reasons why you should buy oils that are minimally processed, that is, cold pressed or extra virgin. Names such as pure, light, and virgin are often used in the marketing of oils but these contain varying amounts of unrefined oils, which results in a lot less antioxidant protection and nutrient value.4
Vitamin E’s job is also enhanced by selenium which is found in nuts (particularly brazil nuts) and seeds. Sesame seeds are a great source of vitamin E. If you like tahini or eat hummus then you will be getting a good source of vitamin E.
Tastes good and keeps hunger at bay for longer!
Although fats have higher calorie content they provide a greater sense of satiety. Nuts and seeds were not a major part of my diet growing up and as I started in college I actively avoided them because they were considered calorific. “Why waste my calories on nuts and seeds when I can eat a big bowl of salad and then have a treat later” I thought. I did have those treats because I was left feeling hungry and unsatisfied. When I look back I can’t believe this was my thought process. I now incorporate nuts, seeds, good oils and lots of oily fish in my meals. Result: I’m less inclined to what to eat something else later!
Stabilising blood sugars for weight loss and reducing your risk of disease down the road..
High blood sugars over time cause weight gain, insulin resistance and diabetes. Insulin is a hormone produced by the pancreas after eating carbs. It helps glucose (sugar) in your blood to be taken into the cells so it can be used for energy. Resistance occurs when the cells are unable to use insulin effectively. So insulin is produced but glucose is not taken up by the cells properly, and then sugar builds up in the blood. Insulin resistance is increasing and many people have it without even knowing! People who are overweight/obese or regularly eat refined and processed foods often have problems handling their blood sugar, and as this continues they become pre-diabetic. They may become ‘hangry’ regularly and experience irritability, reduced concentration and a drop in energy level. Then one day they may visit their GP complaining of things like tiredness, dry mouth, increased thirst and urination, or even blurred vision. Their GP does some tests to check blood sugar levels and low and behold they are pre-diabetic or diagnosed with type 2 diabetes! Previously, insulin resistance and type 2 diabetes were mainly seen in adults but these days both are occurring in children and adolescents. There is something seriously amiss as this is preventable through diet and lifestyle changes!
A higher fat, lower carb diet can help stabilise blood sugars. For some it may be a temporary, in an attempt to re-set the ability to manage sugar and for others it may be more of a long-term approach. It may also help with polycystic ovarian syndrome (PCOS) as women with PCOS have elevated insulin levels and often rely on metformin (a diabetes drug). Refined carbs such as biscuits, sugary cereals, and white breads cause a sharp rise in insulin, and likewise many low fat/low calorie sugary foods marketed to be healthy and supportive of weight loss have a similar effect. It is good to also be aware that large portions of healthy carbs such as potatoes, wholegrain breads, cereals, rice and pasta eaten at every meal can also lead to insulin resistance over time. So the moral of the story is to not fool yourself by snacking on pre-packed convenience foods and watch your portion size….carbs particularly processed/refined carbs or even large portions of unrefined carbs cause a lot of insulin to be released! If you feel tired and bloated after a meal you have likely eaten too many carbs!
What about Saturated fat?
Saturated fat is a type of fat found in animal products such as meat, milk, yoghurt, cream and chesses, butter and eggs and it is also found in some plant foods such as coconut oil and macadamia nuts.
Both Dr Robert Lustig (USA) and Dr John Yudkin (UK) for years researched and argued that sugar especially excess fructose (fructose corn syrup) was more to blame for obesity, diabetes and heart disease than fat. Whether their views and research were disregarded because of food industry influence or insufficient evidence is debatable. The view that saturated fat increases low density lipoprotein (LDL) cholesterol which then causes heart disease is too simplistic. Heart disease and cholesterol levels are influenced by many things. LDL cholesterol is used as a marker of heart disease risk but there are also other biomarkers such as homocysteine and an inflammatory marker called C-reactive protein (CRP) that can give us insight into our risk of heart disease.
I don’t doubt that an excess intake of saturated fat may have some negative effects in the long-term but there is no reason why saturated fat should not be included as part of a healthy balance diet. The other thing about saturated fats is that they are less susceptible to damage by oxygen and can maintain stability at higher temperatures than unsaturated fats. Unsaturated fat can be converted to trans fat at high temperatures and we all know that trans fats are just really bad for you! This is why you are better to use a tablespoon of coconut oil are butter when frying at high temperatures.
The key message is don’t be afraid of fat. Low fat products are unnecessary but if you are having more fat in your diet make sure you also think about the overall amount of calories you are having each day. You will not do yourself any favours if you take half the message and eat more fat and continue to eat everything else! For most people a little bit more fat with less carbs keeps you satisfied without the need for extra snacks.
The first step should be cutting out refined carbs like cereal bars, cakes, biscuits, sugary cereals, white breads and replace them with vegetables, nuts and seeds! According to the New Zealand Herald the All Blacks appreciate the benefits of eating more healthy fats such as nut butters and coconut oil, and limiting sugary foods! My next blog will look at the pros and cons of becoming fat adapted as a tool for weight loss and in sport.
- Gropper, S., Stepnick, A., & Smith, J. L. (2013). Advanced nutrition and human metabolism. (J. L. Smith, Ed.) (6th ed.). Belmont, CA: Belmont, CA : Wadsworth/Cengage Learning c2013.
- Dunford, M. & Doyle, J.A. (2015). Nutrition for sport and exercise. (3rd edition) Stamford, CT: Cengage:
- Schofield, G., Zinn, C., Rodger, C. What The Fat? Sports Performance: Leaner, Fitter, Faster on Low-Carb Healthy Fat. (Kindle Locations 677-680). The Real Food Publishing Company. Kindle Edition.
- Consumer. Now you Know. Available at: https://www.consumer.org.nz/articles/cooking-oil Accessed on 25th November 2015