The Field Work Nutrition Smoothie – How nutritional is it?


This excellent looking smoothie has been created by the guys over at Field Work Nutrition. A big thank you to them for sending me this smoothie recipe to have a look at and review. At first glance this smoothie ticks a lot of boxes. As a big fan of seeds and nuts I was very pleased to see 3 different types of seeds in the recipe. Seeds are normally a rich source of many types vitamins and minerals which makes them a great addition to make a smoothie more nutritional. Let’s get into it and have a look at the complete list of ingredients…

The Ingredients

This smoothie has a pretty diverse range 8 ingredients including fruits, seeds and a new ingredient to SmoothFuel, Spirulina. This new to the market and now very popular “superfood” is actually an algae. It is claimed to help with a great number of medical problems and is in fact around 57% protein. The recipe also calls for Field Work Nutrition’s very own Primo Smoothie Meal. A high protein (20 grams per 52 gram serving) powder that has a variety of whole foods that provide a mix of macro and micro nutrients to help provide essential nutrients.


Nutrients and RDI Values

The Field Work Nutrition Smoothie Scored 71

The Field Work Nutrition Smoothie has achieved a very respectable SmoothFuel Nutritional Score of 71. The SmoothFuel Nutritional Score is a method I use to independently evaluate smoothie recipes based on the nutrients they contain without any bias.

The Positives

For a recipe to score a 71 it has to be doing a lot of things right so let’s analyse the good things that we can take away from this recipe. First of all it has a solid macro nutrient profile. By this I mean we are seeing a relatively balanced proportion of each and every macro nutrient. (The RDI % values are based on a 2,500kcal diet). It is quite normal to see a higher than average amount of fiber in smoothies. Fruits, vegetables and seeds generally contain a high amount of this important macro nutrient. The USDA estimates that the fast majority of us do not get enough fiber in our diet so there is no problem having a little extra here.

Looking at the vitamins we see some moderate to high amounts of many but low amounts of vitamin k, folate, niacin and B12. Including a dose of 1403% of your RDI of vitamin E which I will discuss later. In general the vitamin profile is fine. It has decent amounts but nothing too spectacular. I should mention that the Primo Smoothie Meal has a 2000IU serving of vitamin D3 which has not been included in the analysis above.

Minerals. We have almost your whole day’s need of magnesium, a whopping 370 mg, in addition there is a large quantity of 1336 mg of calcium. We have good quantities of the other minerals too. And then we have another elephant in the room, iron, a 29.8 mg serving which is 373% of your RDI. I’ll talk about this again later.

There is a great ratio of omega 6 to omega 3. General diet  advice is to try and obtain a  ratio of 4:1, that is for 4 grams of omega 6 to 1 gram of omega 3. The problem is that a lot of modern “bad” diet have a much higher ratio, 16:1. This disproportionate amount has negative health consequences.

Finally there is a great amount of antioxidants and polyphenols. At the present time I am not able to find accurate and reliable data for some of the micro nutrients and effectiveness of spirulina. Studies that I have read have claimed that different samples of can spirulina contain significantly different amounts of polyphenols. Despite that, the general consensus is very positive with agreement that spirulina is rich in antioxidant polyphenolic compounds that are suitable for daily consumption.

Points to consider

The smoothie contains very high amounts of two micro nutrients both of which I briefly mentioned before, iron and vitamin E. However this has been done by design and is not simply a poor choice of ingredients. The majority of these two nutrients comes from the Primo Smoothie Meal. The guys over at Field Work Nutrition have designed this specific formula for people with an active lifestyle and in particular endurance athletes. Vitamin E is a powerful antioxidant which can help combat some of the negative consequences of exercise, in particular prolonged endurance exercise. Research has also shown that endurance athletes who train above a certain volume to be deficient in iron.

It is important to look at your lifestyle and work out what your body requires and consume both your macro and micro nutrients in accordance with that. The amounts of vitamin E and iron in this smoothie could be suitable for very active people or endurance athletes but these amounts would be excessive for those who live a sedentary lifestyle. Below you can read more about the RDA of these two micro nutrients with links to the advice established by the National Institute of Health.

The National Institute of Health has established a RDA of 15 mg for both men and women over the age of 14. The upper tolerable limit for men and women over the age of 19 is set at 1,000 mg. So the total amount is well under the upper limit and indeed research has not found adverse effects of consuming excessive amounts of vitamin E in food. However as a word of warning, concentrated forms of vitamin E such as in supplements when consumed at high doses have been shown to be dangerous and should be avoided. This meta-analysis reported a dose of or equal to 400IU as high. This smoothie has a total of around 215IU.

The RDA set by National Institute of Health for men and women over 19 years old is 8 mg and 18 mg respectively with the upper tolerable limit at 45 mg. The same advice holds true for iron as I said about vitamin E. Healthy adults have very little risk of iron overload from dietary sources. Care must be taken however when consuming supplements with high amounts of iron.