So 1st of all, what are the physiological functions of lipids?
Many things... it provides protection for the internal organs, assists in regulation of enzymes, constitutes the majority of the central nervous system and the spinal cord, the formation of all cell membranes, formation of the myelin sheath within the nervous system, the transportation, storage and utilisation of fat soluble vitamins A, D, E and K, a fuel source during lower intensity work loads, storage of energy within adipose tissue, insulation through subcutaneous adipose tissue and lastly the synthesis of steroid hormones.
Lipids that are solid at room temperature are called fats whilst lipids that are liquid at room temperature are called oils.
There are chains/rings of carbon atoms that join together with other atoms which a lot of dietary lipids consist of. These are most commonly oxygen and hydrogen. Smaller units of fats are called fatty acids. Double strength bonds are present, these change the shape of the molecule and allow the lipids to become versatile.
3 fatty acids are attached to a carbohydrate backbone which is called glycerol. Fatty acids are broken off during digestion and used as needed. This happens when fatty acids occur naturally as triglycerides.
Tomorrow I'll move onto the rest about fats/lipids!
Showing posts with label soluble. Show all posts
Showing posts with label soluble. Show all posts
Sunday, 9 February 2014
Nutrition - Carbohydrates
This post will be focusing on carbohydrates...
CHO (Dietary Carbs) is used as fuel but ultimately is sent to the liver and muscles. However, some glucose may enter the adipose tissue, also known as fat tissue. This helps to store up fat.
Energy requirements are significantly met through carbohydrates and fats during normal daily activities though the higher the activity, the more carbs are used as opposed to fat.
Carbohydrates are made up of molecules. These are called saccharides. These are the 3 basic categories:
Sugar/Simple Carbs
Starches/Complex Carbs
Fibre/Non-starch polysaccharides
Simple carbs typically contain 1 or 2 units of sugar which are typically made up from a combination of fructose, galactose and glucose.
Monosaccharides = the single molecules of sugars and disaccharides = the 2 molecules of sugars combined together.
There are 2 sources of simple carbs - Fruit (the healthy option) and the less healthy options like biscuits and cakes.
Fruit contains vitamins and minerals, antioxidants and phytochemicals, high levels of dietary fibre, fructose and glucose in different amounts and a trace of amino acids.
However, the less healthy options (anti-nutrient) contain excessive sugar that's higher than 15g per 100g as stated by the FSA, high energy density, no vitamins or minerals, processed and low quality fats and it also affects the insulin response.
Complex carbs have lots of molecules of glucose combined together in long branch chains, these are called polysaccharides. The polysaccharides are broken down into glucose when eaten, enter the bloodstream and are either metabolised or stored.
All carbs provide energy, however there are 2 different sources - refined carb and unrefined carb.
Refined carbs come from rice cakes, white bread and pasta, white rice, cakes, biscuits and pastries whereas unrefined carbs come from whole grain rice, wholemeal/wholegrain products, fresh and frozen veg, quinoa, sweet potatoes, yams and pulses.
Refined carbs contain excessive sugar, higher than 15g per 100g stated by the FSA, contains no vitamins or minerals and also contains processed, low quality fats. It affects insulin response and has high energy density.
Unrefined carbs contain vitamins and minerals, antioxidants and phytochemicals, high levels of dietary fibre, trace of amino acids and fructose in different amounts.
Fibre consists of cellulose, hemicellulose, lignin, pectin, gums and mucilages (indigestible plant materials commonly found in fruit, veg, grains and beans) as well as non-starch polysaccharide.
Fibre however provides no energy whatsoever though it is important to maintain a healthy body according to some scientists.
Fibre also helps to transport foods through the digestive tract by bulking out the food/faeces, this eases movement. These are called insoluble and soluble.
Insoluble is the protective outer layer of plants. Fruit and veg skins along with most unrefined foods are made of insoluble fibre.
Soluble however is found on the inner part of the plants. It can help to reduce cholesterol by carrying out in stools the fats that have been binded in the digestive tract. These are found in barley broccoli, apples, citrus fruits, beans, oats and prunes.
Next up will be fats!
CHO (Dietary Carbs) is used as fuel but ultimately is sent to the liver and muscles. However, some glucose may enter the adipose tissue, also known as fat tissue. This helps to store up fat.
Energy requirements are significantly met through carbohydrates and fats during normal daily activities though the higher the activity, the more carbs are used as opposed to fat.
Carbohydrates are made up of molecules. These are called saccharides. These are the 3 basic categories:
Sugar/Simple Carbs
Starches/Complex Carbs
Fibre/Non-starch polysaccharides
Simple carbs typically contain 1 or 2 units of sugar which are typically made up from a combination of fructose, galactose and glucose.
Monosaccharides = the single molecules of sugars and disaccharides = the 2 molecules of sugars combined together.
There are 2 sources of simple carbs - Fruit (the healthy option) and the less healthy options like biscuits and cakes.
Fruit contains vitamins and minerals, antioxidants and phytochemicals, high levels of dietary fibre, fructose and glucose in different amounts and a trace of amino acids.
However, the less healthy options (anti-nutrient) contain excessive sugar that's higher than 15g per 100g as stated by the FSA, high energy density, no vitamins or minerals, processed and low quality fats and it also affects the insulin response.
Complex carbs have lots of molecules of glucose combined together in long branch chains, these are called polysaccharides. The polysaccharides are broken down into glucose when eaten, enter the bloodstream and are either metabolised or stored.
All carbs provide energy, however there are 2 different sources - refined carb and unrefined carb.
Refined carbs come from rice cakes, white bread and pasta, white rice, cakes, biscuits and pastries whereas unrefined carbs come from whole grain rice, wholemeal/wholegrain products, fresh and frozen veg, quinoa, sweet potatoes, yams and pulses.
Refined carbs contain excessive sugar, higher than 15g per 100g stated by the FSA, contains no vitamins or minerals and also contains processed, low quality fats. It affects insulin response and has high energy density.
Unrefined carbs contain vitamins and minerals, antioxidants and phytochemicals, high levels of dietary fibre, trace of amino acids and fructose in different amounts.
Fibre consists of cellulose, hemicellulose, lignin, pectin, gums and mucilages (indigestible plant materials commonly found in fruit, veg, grains and beans) as well as non-starch polysaccharide.
Fibre however provides no energy whatsoever though it is important to maintain a healthy body according to some scientists.
Fibre also helps to transport foods through the digestive tract by bulking out the food/faeces, this eases movement. These are called insoluble and soluble.
Insoluble is the protective outer layer of plants. Fruit and veg skins along with most unrefined foods are made of insoluble fibre.
Soluble however is found on the inner part of the plants. It can help to reduce cholesterol by carrying out in stools the fats that have been binded in the digestive tract. These are found in barley broccoli, apples, citrus fruits, beans, oats and prunes.
Next up will be fats!
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