Nutrition Basics


Nutrition

Nutrition consists of the functional components in food that an organism must obtain in order for it to grow and flourish. Nutrition simply put is a collective term for all of the nutrients required by an organism to sustain life and promote health.

“Nutrition is the intake of food, considered in relation to the body’s dietary needs. Good nutrition – an adequate, well balanced diet combined with regular physical activity – is a cornerstone of good health. Poor nutrition can lead to reduced immunity, increased susceptibility to disease, impaired physical and mental development, and reduced productivity.” – (World Health Organisation)

Nutrients
Nutrients are the organic and inorganic substances found in plant and animals material deemed biologically functional to an organism’s physiological demands. Simply put, nutrients support the functioning of an organism on a cellular level. There are two types of nutrients; Essential nutrients, of which the body cannot biosynthesize (or can but in inadequate amounts) which must be obtained from diet and non-essential nutrients, of which the body can biosynthesize in sufficient quantity.

“Food provides a range of different nutrients. Some nutrients provide energy, while others are essential for growth and maintenance of the body. Carbohydrate, protein and fat are macronutrients that we need to eat in relatively large amounts in the diet as they provide our bodies with energy and also the building blocks for growth and maintenance of a healthy body. Vitamins and minerals are micronutrients which are only needed in small amounts, but are essential to keep us healthy. There are also some food components that are not strictly ‘nutrients’ but are important for health, such as water and fibre.” – (British Nutrition Foundation)

Macro/micro-nutrients
There are six main essential nutrients carbohydrates, fats, protein (the macronutrients), vitamins, minerals (the micronutrients) and water which is also considered an essential nutrient.

Macro-nutrients are generally obtained from the diet in amounts ranging anything from tens of grams to hundreds of grams. For example the protein requirements are based on the “RNI” (Reference Nutrient Intake) and for an average UK adult is 0.75g per kg of body weight, which is 53g for a 70kg adult. Compare this to carbohydrate requirements, based on “DRV’s” (Dietary Reference Values), which are 50% of total energy intake which would be 313g on a 2500 kcal diet.

Micronutrients however, are required in far smaller amounts and are measured in milligrams and micrograms. Intakes are based on the RNI’s and are based. The dietary recommendations for intakes of B12 for example are so small the amount needed would fit on the tip of a pin since only 1.5 micrograms is required.

Non-essential nutrients are nutrients which do not need to be directly obtained via the diet since they are indirectly obtained via substrates and can be synthesised endogenously (within the body). Non-essential nutrients mainly consist of the non-essential amino acids, but also nutrients such as inositol (vitamin B8) and certain minerals are also considered non-essential, although this does not undermine the importance of these nutrients for our health.

Phytochemicals
There are of course very important components of foods that do not get official recognition as “essential nutrients” although their exclusion from this category might mislead one to think they’re not as important. They are, and arguably more so when the aim is to optimise health. Phytochemicals are beneficial non-nutritive components of foods such as vegetables, fruits, whole grains, herbs, nuts and seeds. These plant chemicals include phenols, terpenoids, sulfurs compound, pigments and other antioxidants, all of which have shown to promote significant health benefits and may have specific preventative implications for certain disease including cancer and cardiovascular disease.  

Is diet enough to obtain all the nutrition we need?
Absolutely. Most people should be able to get all the nutrients they need by eating a healthy, varied diet, including multiple colours and fruit and vegetables. However, there are a few exceptions where supplementation may be wise or even necessary. For example, if a woman is planning to conceive a child it is recommended they take a folic acid (vitamin B9) supplement to prevent congenital birth defects. Unless of course you can consistently consume at least 300 mcg of dietary folate, supplementation is a sensible option. Spina-bifida can occur in Mothers whose B9 intake is insufficient before conception and particularly during the first 12 weeks of pregnancy. Vitamin D is another vitamin in which it is difficult to obtain in sufficient amounts all year round from food and sunlight alone. This is even more the case for vulnerable groups such as pregnant women, the elderly, Muslims who veil the skin, those with dark pigmented skin such as Asians and Africans, children and also Caucasians with fair skin. Current research now supports the idea that most people would benefit from vitamin D supplementation as current intakes and levels of UVB exposure are inadequate, especially for building reserves for winter. Moderate to high dose supplementation may also be a necessary requirement for those or are clinically deficient as to consistently raise serum levels from deficiency status into adequate ranges, which even then could take months.

 

Bibliography

Barros, L. and Ferreira, I. (2017). Editorial: Phytochemicals and their Effects on Human Health. Current Pharmaceutical Design, 23(19).

Holick, M., Binkley, N., Bischoff-Ferrari, H., Gordon, C., Hanley, D., Heaney, R., Murad, M. and Weaver, C. (2011). Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology & Metabolism, 96(7), pp.1911-1930.

Nutrition.org.uk. (n.d.). What are nutrients? – British Nutrition Foundation. [online] Available at: https://www.nutrition.org.uk/healthyliving/basics/what-are-nutrients.html [Accessed 20 May 2016].

R, J, BERRY et al. (1999) PREVENTION OF NEURAL-TUBE DEFECTS WITH FOLIC ACID IN CHINA. The new England journal of medicine. [Online] Available from: http://folictrial.org/wp-content/uploads/2009/09/Prevention-of-neural-tube-defects-with-folic-acid-in-China.pdf [Accessed on 7.2.15]

Who.int. (n.d.). WHO | Nutrition. [online] Available at: http://www.who.int/topics/nutrition/en/ [Accessed 20 May 2016].

A role model for healthy eating

Who do you think are the best role models for your child’s eating habits? Can you do anything to change your child’s stubborn eating ways? Well, if any of these questions intrigue you, we may have some advice for you. But brace yourself, it may require some fancy-dress, Yoda like patience and persistence more stubborn than your child’s resistance to embrace the plant side…

 

Research has specifically investigated who are the most influential role models for your child’s eating habits. Its was found that Mothers are better models than strangers (harpers and sanders 1975) which should come as no surprise. Older children are better models for your child than other younger children (birch 1980), but fictional superheroes, not even limited to the child’s favourites, are better models for shaping child eating behaviour than all of the above! (birch 1999). Okay now I’m not suggesting that you ask Spider-man to have dinner with your children every night. I’m also not suggesting you dress up as your kid’s favourite superhero every night either (although that certainly wouldn’t be a bad idea). I am however trying to highlight how important it is to have responsible eating models around your children. Remember these models can play a role in promoting healthy and unhealthy food…

 

Very few kids actually are fussy eaters. Many children who repeatedly turn down their greens do so because of an evolutionary innate fear of consuming poisonous vegetation. Simply put many children are naturally fearful of vegetables for evolutionary reasons. This trait would’ve served children well some 20,000 years ago, but now, unfortunately for parents who are trying to get Timmy to eat his veggies, it’s just an vestigial annoyance that often results in wasted food. Good news is, research has given it a name and found solution. The term neophobia is given to describe a fear of novel foods (new foods). Parents will often try feeding novel foods, often the form of vegetables but may give up after only 3 or 4 tries prematurely concluding that their child dislikes X food. However, researchers found that children will refuse novel foods (often in the form of green vegetables) from anywhere between 9-15 times before perceiving the food as safe. That’s a lot of turning down veggies before they accept the food as a part of their food preferences. So the take home message is persist with veggies in small amounts on the plate each day until your child deems the food as safe…

Certainly a child’s reluctance to eat certain foods can be both frustrating and worrying but by following our weekly tips you can help transform your kids eating habits from fussy to veggie in no time!

“Good” carbs vs “Bad” carbs

 

Introduction

For many people and particularly dieters, carbohydrates have had a sinister stigma attached to them for many years now. Their reputation has evolved from the understanding that they are a significant contributing factor in the cause of weight gain, as well as their association with promoting disease conditions. Because of this it has led to many misconceptions and fear of consuming Carbohydrates. In this article the differences between the generic terms of “good” carbs and “bad” carbs will be discussed using complex carbohydrates and simple sugars as prime examples will be discussed. In particular the physical states and physiological responses to both types will be discussed outlining key points for health and improving body composition.

Key factors when it comes to carbohydrates

  • choose low G.I carbohydrates
  • choose the ones highest in fibre
  • look for the ones rich in minerals, vitamins and if possible protein
  • go for natural and whole not refined and processed
  • refrain from over cooking and over boiling them
  • add protein or fat to your carbohydrates to lower its G.I rating

The dark side of carbohydrates

The reality is that in today’s society, lifestyle and dietary related diseases are on the rise with diabetes being the leading threat to human health along with heart disease. Right now more than 3.7 million UK people are suffering with type II diabetes. The ironic thing about this fact is that type II diabetes is a completely self inflicted condition caused by bad dietary habits, specifically from the excess consumption of refined carbohydrates. The sad thing about this is that type II diabetes is completely reversible if tackled early enough and yet unfortunately it is on the rise and is estimated to hit 5 million people by 2025 [1]. Our current high refined carb diet may have been encouraged by much earlier warnings about the increasing rate of ischemic heart disease caused by the high consumption of saturated fats at the time. The warnings encouraged a decrease in the intake of fats in favour for eating more complex carbohydrates [2]. This has resulted in mass confusion as many people today still believe the complex and simple carbohydrates term is an effective way to distinguish between “good” and “bad” carbohydrates. Unfortunately the truth is, excuse the pun, less simple and more complex then that.

Good or bad carbohydrate?

As I will explain in another article there is no good or bad carbohydrate per se, there can be a time and a place for both particularly for those participating in sports. But there are some key differences and reasons as to why one type is generally considered to be “bad” and one is considered to be “good” and I’d like to address the differences between the two.

Simple sugars, as the name implies, have simple chemical structures made of monosaccharides (single sugar units). Simple sugars like glucose for example are said to be “bad” as they are absorbed through the intestinal tract quickly promoting a hormonal response (releasing insulin) that causes weight gain, fatigue and sugar cravings. Complex carbohydrates due to their complex chemical structure as the name implies, is made up of a complex chain of disaccharides and polysaccharides, (two or more sugar units combined). Complex carbohydrates like the sugar lactose for example is a disaccharide its made of two sugar units glucose and galactose and is said to be “good” as they are absorbed and digested slowly. Very little insulin is released from complex carbs and the conventional understanding goes that complex carbs provide a slower release of energy from the food and they help improve fat burning. But why is insulin bad and how does it cause weight gain? Well this depends entirely on ones insulin sensitivity.

If your muscle cells are insulin sensitive at the time of consuming simple carbs the muscles are primed to absorb the glucose and convert it into its stored form, glycogen. If your not insulin sensitive when consuming simple carbs the path way for glucose storage in skeletal tissue is closed and the flood gate is open to fat cells. This is how and why people get fat from simple carbs like sugary sweets and this is why its best to consume complex carbs at times when insulin sensitivity is low.

The answer to the next question, how do you know whether your muscles are insulin sensitive or not, depends on many factors. Your insulin sensitivity will be higher if you are in an active state, a fasted state or if your glycogen levels are depleted. For example first thing in the morning and after an intense workout your insulin sensitivity will be higher so consuming simple carbs will actually help with recovery and will refill depleted muscle energy. On the contrary if you eat the same type of simple carbs late at night in an inactive and rested state, insulin sensitivity will be low which as mentioned will promote fat storage. Consistently high insulin levels (on top of causing weight gain, fatigue and sugar cravings) can eventually lead to insulin resistance and type II diabetes. So in conclusion the conventional understanding goes simple = fast digesting and complex = slow digesting. However relying solely on this simple and complex classification is not wholly accurate and can often be confusing and misleading and here’s why…

Simple doesn’t always mean fast digesting, complex doesnt always mean slow digesting

Fruits are considered sources of simple sugars and yet some types of fruit despite their simple chemical structure release their glucose slowly into the blood stream which keeps insulin levels low. This contradicts the simple = fast digesting mantra. Conversely waxy maize starch is a complex carbohydrate yet it digests so fat its comparable to glucose. Insulin and glucagon compete with each other, insulin is a storage hormone, glucagon breaks down energy stores, when you have high levels of circulating insulin your body is in storing mode and glucagon will be low therefore you are not in energy burning mode. Some fruits which are considered a simple sugar, don’t actually impact insulin dramatically because of the slow release of energy which of course equates to steadier sugar levels, reduced cravings and appetite, better mood and enhanced fat burning. This would be considered by many to be a positive hormonal response, if your health and body weight is of any concern. In fact fructose the simple sugar found in fruit despite it being simple has even shown to be useful in treating people with type II diabetes due to its slow digesting nature [3].

In contrast some types of complex carbohydrates, white rice for example, despite its complex chemical structure is broken down and absorbed quicker then some simple carbohydrates and would technically put them in the category of being a “bad” carbohydrate based on the negative hormonal response from the body. Basically because white rice considered a complex carbohydrate causes high amounts of insulin to be released which blunts glucagon production meaning no fat burning or burning any stored energy, energy spikes and crashes, sugar cravings and weight gain, all despite the fact it is complex which is considered “good”. This of course is why it causes what is considered to be a negative hormonal response.

So as you can see, it’s this inaccurate classification of carbohydrates that has led to a huge misconception about what’s healthy and what isn’t. This somewhere down the line has contributed to the huge increase in refined carbohydrates leading to a continuous flurry of health problems worldwide.

The glycemic index scale

So how can we tell what’s good or not? The glycemic index is a reliable and practical way of determining a good choice of carbohydrate, it’s very basic and easy to use and understand. The glycemic index was devised for people who were diabetic and trying to manage their blood sugar levels. The G.I index is a measurement based on a percentage of how quickly 50g of a carbohydrate enters the blood stream compared to glucose which enters the bloodstream almost instantly and has a GI rating of 100. So say a baked potato has a GI rating of 85 it means the baked potato digests and releases its glucose into the bloodstream nearly as fast as glucose, only 15% slower, or in other words 0.85x the speed glucose would enter the blood stream. Since low glycemic index (low G.I) carbs are digested slow and release their energy slowly they are better for keeping sugar levels steady and healthy therefore should be the prime choice of carbohydrates for those managing diabetes and especially for those trying to avoid it [4]. High glycemic carbs on the other hand are digested quickly and therefore release their energy too quick and are not considered good choices for our health among many other things such as energy levels and appetite [5].

High GI vs Low GIexamples of low vs high GI foods

Carbohydrates that digest quickly, like white rice for example will have a high glycemic index (high G.I) that promote the release of insulin from the pancreas to regulate the high amounts of sugar rapidly entering the blood. This fast acting regulatory endocrine system is important to us because the sugar in excess will actually poison the blood. However insulin is a double edged sword since insulin is a storage hormone and is directly responsible for the deposit of glucose into adipose tissue leading to weight gain. Further more repeated and chronic insulin responses from the continuous consumption of high GI carbohydrates will lead to decreased insulin sensitivity. When this happens insulin no longer has the same effects on glucose metabolism it once had. Similar to taking a drug continuously your body eventually becomes tolerant to it, consuming refined high GI carbohydrates day in day out is the same thing but in this case you become resistant to your bodies own natural mechanism of controlling its blood sugar via the release of insulin. The end result at the very least is insulin resistance and clinical diagnosis of type II diabetes [6]. Low GI diets have long shown in studies on obese subjects that not only do they improve insulin sensitivity but they also increase fat oxidation and reduce waist circumference compared to those on high GI diets [7].

That excludes other benefits such as increased and sustained energy release, improved mood, less cravings and decreased cholesterol etc. Carbohydrates are certainly not the enemy but I would say misunderstanding them most definitely is.

What to look for

There are obviously a few components when it comes to determining what sources of carbohydrate are the best to consume but they can be summed up by a few simple differences. You should always choose more natural wholesome sources of carbohydrates that are high in soluble or insoluble fibre and are rich in nutrients like vitamins and minerals. The more wholesome and less refined a carbohydrate is generally the better. Refining of a carbohydrate really makes no sense because its a process of stripping a once wholesome and natural food that was full of fibre and nutrients down essentially to nothing but starch. The reason this is done is mainly to increase shelf life which of course benefits the companies selling it, as refined fibre reduced carbohydrates are less susceptible to go off. Cooking carbohydrates also changes its digestibility and therefore can increase its G.I rating, so a baked potato would have a higher glycemic index compared to a raw one, the same applies to food when you boil it too. In contrast adding fat and/or protein to a meal containing carbohydrates will actually lower its G.I rating. This is why consuming protein with every meal is recommended for fat loss.

Summary

  • choose low G.I carbohydrates
  • choose the ones highest in fibre
  • look for the ones rich in minerals, vitamins and if possible protein
  • go for natural and whole not refined and processed
  • refrain from over cooking and over boiling them
  • add protein or fat to your carbohydrates to lower its G.I rating

Conclusion

It’s clear from all of the evidence long term consumption of refined carbohydrates is a recipe for the decline in the future of human health. In summary as humans if we are to stay healthy, disease free and also wish to maintain a healthy weight, low G.I carbs should be the main source of carbohydrates for everyone looking to avoid insulin resistance, diabetes and especially for those who want to avoid unnecessary weight gain, feelings of fatigue and repeated sugar craving cycles. The long term consumption of high G.I carbs is a slippery slope and we must all work together to stay off for the good and the benefit of our future generations to come.

[1] http://www.diabetes.org.uk/documents/reports/nhs-health-check-lets-get-it-right-0912.pdf

[2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2869506/

[3] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2682989/

[4] http://www.ncbi.nlm.nih.gov/pubmed/23705645

[5] http://www.diabetes.org.uk/Guide-to-diabetes/Managing-your-diabetes/Glycaemic-Index-GI/?gclid=CjwKEAjwxtKeBRDMzoeQmYn5uHcSJACGCF3D1mPlKw9KXkfkcUMg3zlXVwRxvMUnLj6wn_C3v3Zg-RoC8Tbw_wcB

[6] http://www.ncbi.nlm.nih.gov/pubmed/19934403

[7] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3937245/