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Week 10 - Palm oil

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Palm Oil Having looked at different types of fats, their uses in living organisms and explored the causes and implications of obesity the final week is going to focus on one source of lipids that has seen a dramatic increase in demand and is having a devastating effect on the environment. Palm oil accounts for two-thirds of internationally traded  vegetable oils. Worldwide, over 54 million tonnes of palm oil  were produced in 2013. It is used in a plethora of food and  cleaning products. You’ll find it in peanut butter, ready-made  pizzas and shampoos. It’s used because it’s cheap to produce and  has a longer shelf-life than other oils. The downside to all  this cheap oil is that millions of hectares of rainforest  have been converted to palm oil plantations,  posing a major threat to biodiversity. It’s not just charismatic animals like  orang-utans that lose their habitats.  Each 1,000 hectares of rainforest is  estimated to be home to 750 tree  species, 400 bird speci
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Week 9- Epigenetics & Obesity

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Epigenetics & obesity Our understanding of genetics has grown rapidly over the last few decades. One of the newest areas of interest is epigenetics . Your DNA is contains all the genes you've inherited, and this is fixed, but the DNA can become more and less coiled, as a result of exposure to different chemicals, stressors and environments. The more coiled DNA is the less likely the genes are to be expressed, but if the it becomes less coiled, the genes can be read and expressed, altering your characteristics.  There have been a number of observations of humans and the effect of famines on obesity levels in subsequent offspring. Have a look at this article on the dutch famine:  http://www.naturalhistorymag.com/features/142195/beyond-dna-epigenetics There have also been a number of animal studies, usually on mice to test the validity of these claims. Have a look at this article:  http://www.the-scientist.com/?articles.view/articleNo/45558/title/Obesity--Diabetes--and-
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Week 8- Obesity Genes

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‘Three-year-old dies of obesity’  screamed the newspaper headlines  when, in May 2004, a child died from  heart failure in a London hospital.  She weighed a staggering 40 kg.  A media frenzy erupted, and the  parents were blamed for ‘stuffing  her to death’.  Was it fair to accuse her parents?  Scientists later confirmed that there  was a medical problem behind the  child’s extreme obesity: a genetic glitch  that triggered her immense appetite. Genes play a crucial role in shaping  our weight, but scientists have only  recently started to work out how.  It is too simple to say that obesity  is ‘all in the genes’ but our genetic inheritance does have a big say in  our size. Researchers can come at obesity f rom two directions. In a ‘classical’  approach, the extent to which  weight or obesity is inherited can  be assessed. This is a difficult area  to study, but the consensus is that  there is a high degree of heritability  in body weight. Obesity genes A newer approach is to
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Week 7- Does obesity matter?

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Does Obesity Matter? Worldwide obesity has more than doubled since 1980. In 2014, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 600 million were obese. 39% of adults aged 18 years and over were overweight in 2014, and 13% were obese. Most of the world's population live in countries where overweight and obesity kills more people than underweight. 41 million children under the age of 5 were overweight or obese in 2014. Obesity is preventable. Raised BMI is a major risk factor for noncommunicable diseases such as: cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012; diabetes; musculoskeletal disorders (especially osteoarthritis – a highly disabling degenerative disease of the joints); some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon). The risk for these noncommunicable diseases increases, with increases in BMI. Childhood obes
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Week 6- Too much fat

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Too much fat: According to the World Health Organisation (WHO): Worldwide obesity has more than doubled since 1980. In 2014, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 600 million were obese. 39% of adults aged 18 years and over were overweight in 2014, and 13% were obese. Most of the world's population live in countries where overweight and obesity kills more people than underweight. 41 million children under the age of 5 were overweight or obese in 2014. Obesity is preventable. But what is obesity? Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m 2 ).  BMI is best used as a guide line as it can be inaccurate. For example athletes have a h
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Week 5- Fat Functions

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Fat Functions: In previous week we have already looked at the role of omega-3 and cholesterol in the body. This week we are going to overview functions of lipids in the body and ensure we have a full understanding and appreciation of their importance to living things. 1 . Lipids are a an incredible source of energy  for living organisms. Gram for gram fats release twice as much energy as carbohydrates and it also releases valuable water in the process. In order to become a fuel for respiration triglycerides are split into their main substituent parts; glycerol and fatty acids. For  those of you that are familiar with the process of cellular respiration t he glycerol molecule is split and is incorporated into the glycolysis pathway and the 3 fatty acid chains are also split by enzymes before joining the krebs cycle . The reason fats release more energy is because as the fatty acids are broken down they are oxidised , losing  hydrogen. These hydrogen ions are useful in other place
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Week 4- Close-up on cholesterol

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Close-up on Cholesterol: Cholesterol belongs to a family of lipids called steroids, which have a common structure (see diagram above), very different to the triglycerides we have met before.  Our notion of cholesterol as bad is overly simplistic. When we say "cholestrol" we are actually referring  to two different cholesterol transporters found in the blood: high-density and low-density lipoprotein, otherwise known as HDL (‘good’) and LDL (‘bad’) cholesterol.  Raised levels of LDL cholesterol are generally associated with an  increased risk of heart disease. According to most sources, it is not eating high-cholesterol foods, such as eggs, that drives up our blood cholesterol levels, but eating foods that are high in saturated fats. This is because our livers turn saturated fats like those in cakes and pastries into LDL cholesterol in the blood. The past few years have seen continued questioning of dietary guidance on saturated fats and cholesterol. However
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Week 3- OMG Omega 3

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OMG Omega 3: Polyunsaturated fats are widely regarded as "healthy fats". These are essential in our diets for a range of functions.  There are two main types of polyunsaturated fats: omega-3 and omega-6.  Some types of omega-3 and omega-6 fats can't be made by the body and are therefore essential in small amounts in the diet. Omega-6 fats are found in vegetable oils.  Omega-3 fats are found in oily fish. Good plant sources of omega-3 fats include flax seeds, walnuts, and canola or soybean oil. Most of us get enough omega-6 in our diet, but we're advised to have more omega-3 by eating at least two portions of fish a week, including one of oily fish.  But why? What are the benefits of omega-3? Task: On paper write 6 bullet points about omega-3. Include the following: The ratio of omega-3 to 6, Which foods we should consume to up our intake, The associated health benefits of omega-3. You may find the following websites useful. If you choose to do yo
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Week 2- Which fats in what foods?

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Which fats in what foods? Last week your research found out that saturated fatty acids only contain single carbon to carbon bonds, whereas  unsaturated fatty acids contain one or more double bonds. We can add more detail to this; unsaturated fatty acids can be cis , with both hydrogens either side of the double bond being on the same side, or tans , where the hydrogens either side of the double bond are on opposite sides. Trans fats are frequently formed artificially using a process called hydrogenation . This process is used to make oils, which are usually a liquid at room temperature, harder and solid, for use in spreads or industrial baking. This process involves reacting fats with hydrogen, either resulting in  complete hydrogenation, where all double bonds are removed, or partial hydrogenation , where the position of the hydrogens either side of the double bond shifts from cis to trans.  These changes in structure increasing the molecules melting point meaning it is solid a
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Week 1 - Introduction

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Introduction: Fat is such a contentious issue. It dominates discussions about body image, costs the NHS millions each year, is restricted and demonised by many weight loss  programmes and yet is absolutely essential to the correct functioning of healthy organisms. This MOOC will explore some of the issues surrounding fat. We will look at the debates around different sources of fat, the importance of fats in the body and the health implications of excess fats.   Each week you will have a task to complete that will help you develop your knowledge and understanding of fat and associated topics. Tasks will be subtitled at the bottom of each weeks page. They will involve adding a comment to the MOOC page and completing written summary, no more that 1 A4 side per week, for you too keep as a record of you learning on this MOOC. Some weeks also include fat fanatic tasks that go off on a bit of a tangent that you may want to explore. Fat terminology: This week we will start be clari
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