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Food substitution

Humans love to eat. Yes, we need to eat to stay alive, but many people live to eat.

With increasing urgency food sustainability and ethical concerns are necessitating an exploration of other avenues to meet the public’s nutritional needs. There is little doubt that the current global population, standing just shy of 8 billion, cannot be fed indefinitely on the available resources if current eating habits remain unchanged. Western societies’ appetite for select cuts of beef (fillet and sirloin steak), fish (salmon and tuna fillet), chicken (breast), eggs (consumed at breakfast and omnipresent in a multitude of baked goods), and dairy (ubiquitous in most food products), to name but a few, contribute to food waste and rapid depletion of natural resources. Throw disease, ill-health, and obesity in the mix, and the quest for an alternative food objective comes to the fore.

Image credit: Lotus_studio at

Food poisoning

We would like to believe that all food products are safe for consumption, yet in 2018 alone there have been many reported cases of Salmonella, a common cause of digestive upset. The sources include shelled eggs, chicken salad, kratom, raw sprouts, dried and frozen shredded coconut. The recent outbreak of listeriosis (caused by the bacterium Listeria monocytogenes) in South Africa is reported to be the largest, according to the World Health Organisation (WHO). The infection has reportedly caused 180 deaths and infected almost 1000 people since January 2017. The main food culprits include dairy products, ready-to-eat meat, and fish. Even though cooking methods are said to destroy these bacteria, it is understandable that consumers might be tempted to consider a vegan diet given that all animal derived food options (a common cause of contamination) will then be eliminated from the diet. Given that modern day life sees the public eat more convenience or take out meals (often subject to questionable hygiene practices) as opposed to meals cooked from scratch in the family home, surely avoidance is preferable to even a slight chance of infection. Our ever increasing frenetic pace dictates lifestyles vastly different to those of the 1950’s where housewives were encouraged (actually expected) to welcome their husbands to a three course home cooked meal at the end of the working day. Those people caught in the rat race clearly need a different food objective rather than being told to re-introduce the 1950’s home economics norm.

What is the solution?

Vegetarians and vegans alike fly the flag for alternative food options motivated by ethical, moral, and health beliefs. Food manufacturers are responding to these dietary demands and meat and dairy free alternatives are becoming increasingly available. Just like gluten free options, food products are progressively being labelled as vegetarian or vegan for ease of purchase. Judging by consumer willingness to acquire these options, even at inflated prices, this corner of the market is set for growth.

The importance of optimal nutrition and nutrient intake is not confined to mouse studies in laboratories. Nutrient deficiencies are deemed an important long-term health risk and agencies across the world spent an inordinate amount of time and research in addressing these preventable health states and applying strategies in affected communities.

Ethics and moral objections aside, when we replace a beef burger with a meat free alternative, is the consumer getting comparable macro- and micronutrients to support a positive long-term health outcome?

Does our increasing desire to be kind to animals ensure that we humans are adequately nourished?

Macronutrients include protein, fats, and carbohydrates and health organisations across the globe have set clear guidelines with regards to the quantity of each that are needed in the daily diet to support health outcomes and prevent nutrient deficiencies. Yes, there is a lot of talk of late about augmenting certain parts of the guidelines. Just look at the Palaeolithic diet vs vegan debate. The low carbohydrate high fat (LCHF) information sheet is the polar opposite to that of the Forks Over Knives template. Professor Tim Noakes, South African scientist and emeritus professor in the Division of Exercise Science and Sports Medicine at the University of Cape Town, is an avid advocate of the Banting diet to successfully address diabetes. This diet focuses on animal derived protein, high in fat (even saturated) at the expense of carbohydrate or starch option such as breakfast cereals, rice, pasta, and bread. Dr Dean Ornish, M.D., is revered for his plant-based diet to address cardiovascular disease, a stance against diets high in animal protein and saturated fat. These two prominent researchers’ findings are in direct conflict and yet both claim to be holding the answer to a positive long-term health outcome.

When we consider dietary guidelines, will avoiding all animal derived food ensure that consumers consume the recommended nutrient intake?

We rely on food to provide energy and a few decades ago a vast percentage of the human race would be so severely malnourished that any source of calories was the difference between life and death by starvation. Access to food has significantly improved and even though many people can still struggle to find enough to survive, most people in the West have access to an abundance of calories, albeit not necessarily equal to vital nutrients. If we are to believe the multitude of food advertisements, we are at risk of energy deficiency. The recent directive from Public Health England to reduce children’s snacks to 100 calories elicited public outrage. The mainstream belief is that the human race will soon be extinct if we curb our calorie intake, despite the alarming rise in obesity. Causes of obesity are multifactorial, yet there is little argument that most people are eating too much of the wrong food – ultra processed, energy dense, sugar laden, junk options – and exercising too little.


A growing number of nations across the Globe choose a boxed cereal and milk as their default breakfast option. Fuelled by frenetic lifestyle, convenience, cost, and aggressive advertisement, breakfast cereals are not likely to be replaced by agreeable substitutes any time soon. This sugar rich, first meal of the day is traditionally served with a controversial accompaniment, milk. Arguments against whole cow milk include the high saturated fat content reportedly unsuitable for heart health, lactose content associated with digestive symptoms (diarrhoea, gas, and bloating), and bovine milk protein intolerance related to food sensitivities and eczema. This excludes the controversy surrounding the ethical treatment of dairy herds and the slaughter of male calves as a direct result of factory farming.

It is small wonder that milk alternatives are selling like proverbial hot cakes. The various options are all suitable for ethical vegetarians as they are 100% plant based. The obvious choice, soya, is stocked in most coffee shops and therefore easily accessible. The concern with increasing soya intolerance and sensitivity, however paves the way for a myriad of other choices, almond, hazelnut, coconut, rice, and oat.

The first question regarding nutrient intake that arises is, if you are replacing a protein dense milk option (whole, skimmed, or semi-skimmed cow milk) with an alternative to accompany an already carbohydrate rich breakfast cereal, are you running the risk of protein deficiency? The second consideration is, are you turning that all important first meal of the day into an unsuitable sugar rush? Excess sugar is correlated with obesity, one of the leading causes of type II, or late onset, diabetes. A quick search on any social media platform highlights the fact that the ‘war on sugar’ is in full swing. Sugar tax and increasing availability of substitute sweeteners (xylitol, stevia, and even coconut sugar) show that the tide is changing.

From a micronutrient point of view, most milk substitutes are fortified with any of the following: calcium, vitamin B2, B12, and D, mooting the argument that vegans do not gain any of these vitamins from their daily diet. If we accept fortification as a viable health strategy, the obvious solution would be to add protein to this popular style of breakfast. Given the overwhelming popularity of instant food, it might be too big an ask for consumers to add a suitable vegan protein option (nuts or seeds), thus instead necessitating manufacturer supplementation, similar to that of the specific micronutrients mentioned above.

ProductProtein per 100 gFat per 100 gCarbohydrate per 100 gCalories per 100 g
Whole milk (pasteurised)
Skimmed milk (pasteurised)
Semi-skimmed milk (pasteurised)
Alpro® Soya milk (fortified)*
Alpro® Almond milk (fortified)*
Alpro® Coconut milk (fortified)*
Alpro® Hazelnut milk (fortified)*
Alpro® Rice milk (fortified)*
Alpro® Oat milk (fortified)*

Dataset: McCance & Widdowson 2015, *Alpro website

Fast Food Options

Looking beyond breakfast, if we consider a very popular fast food option, a beef burger, what nutritional impact do we see when ground beef is substituted with a grilled portobello mushroom, a classic barbecue favourite?

Clearly from a calorie point of view this is every dieter’s dream and the vast reduction in fat will make heart foundations across the world celebrate. The proverbial can of worms is opened when we calculate the loss of protein at a staggering 89%. Put another way, a comparable amount of portobello mushroom gives you a little over one tenth of the protein you would receive when eating the same amount (per weight) of minced beef patties. Yet again, an easy solution would be to add a suitable source of vegan protein, such as beans, nuts, or seeds. Given that most consumers opt for extra cheese, bacon, or multiple beef patties, what would prevent non-meat eaters from adding their chosen, protein rich, extras?

ProductProtein per 100 gFat per 100 gCarbohydrate per 100 gCalories per 100 g
Barbecued minced beef patties29.616.20264
Grilled portobello mushroom*

Dataset: McCance & Widdowson 2015 and *Google

Dinner is served

Another firm dining favourite is spaghetti bolognaise. The vegetarian substitute for beef mince is Quorn™ and the vegan option is textured vegetable protein (TVP), derived from soya beans. The benefit of animal-derived protein is that it is almost always provides high protein and zero carbohydrates. Remember that the modern day diet is already laden with energy dense carbohydrates (pasta, rice, potatoes, bread, cereals, biscuits, crackers, and crisps). Therefore, when substituting a high protein rich food with one that contains an increasing percentage of carbohydrates results in an even greater starch intake at the expense of vital protein. It does not matter that you are an ultra marathon runner and able to burn off those extra calories via intense exercise. The experts in sports science nutrition advocate less focus on carbohydrate loading and more on post training protein intake to support adequate muscle repair. Elite athletes aside, most people are more sedentary than their forefathers and health guidelines strongly encourage us to consume fewer calories per day, even though the calorie debate is often a bone of contention.

ProductProtein per 100 gFat per 100 gCarbohydrate per 100 gCalories per 100 g
Minced beef patties19.716.20225
Quorn™ mince*

Dataset: McCance & Widdowson 2015, *Quorn website, **Wholefoods website

Nutrition conundrum

Health directives stating that we have to consume fewer calories but maintain our protein intake (conservatively set at 0.75 g of protein per body kg of weight) lead us to an impasse. Clearly substituting animal derived food options with vegan alternatives sees a significant reduction in calorie intake in most cases. The difficulty arises when we follow nutritional guidelines for protein intake. To maintain a comparable intake of vital protein on a vegan diet it seems that greater quantities of food need to be consumed, unless the bulk of the diet is based on TVP. In that case a reduction in calories no longer applies.

It is imperative to note that even though fruit and vegetables do contain protein, the amount simply is not comparable to that found in nuts and seeds, tofu, legumes, or indeed animal-derived sources. For example 100 g of raw, mature, spinach supplies a mere 2.8 g of protein. If a 50 kg ( 7 stone 9 pounds) adult woman were to rely on spinach for her overall protein needs (50 x 0.75 = 37.5 g), she would need to dish up a staggering 1.3 kg versus 190 g minced beef, 155 g grilled salmon, or indeed 150 g tofu (these values can fluctuate greatly between individual products).

Animal derived food substitution, with few exceptions (e.g. hempseed, sesame seeds, Brazil nuts, and tofu) lead to a significant increase in carbohydrate intake. The belief that the brain needs glucose derived from carbohydrate or starch rich foods is currently being challenged and is outside of the scope of this article. The most notable changes in macronutrients intake occurs in terms of fat and carbohydrates. Nuts and seeds aside, legumes and soya derived products contain less overall fat, particularly saturated fat, still widely considered a risk factor for cardiovascular disease. They all, however, include a significant amount of carbohydrates, which in itself is not a health risk factor. What is worth assessing is when food substitution occurs without giving these finer points any consideration. Take the roast meat out of a Sunday meal and what remains? Starchy vegetables. Take the meat out of a hamburger and fries meal and what remains? Bread, fries, a lettuce leaf, and a slither of tomato. Take the smoked salmon out of an afternoon tea sandwich and what is left? Bread and margarine.

ProductProtein per 100 gFat per 100 gCarbohydrate per 100 gCalories per 100 g
Almonds (toasted)
Brazil nuts14.368.23.1683
Egg (chicken, boiled)13.00052
Minced beef patties19.716.20225
Tofu (steamed, fried)23.517.72.0261
Red kidney beans (canned in water, reheated)6.90.615.792
Red and brown lentils (whole, dried, boiled)8.80.716.9105
Salmon, wild, grilled25.911.80210
Spinach, raw, mature2.80.81.625

Dataset: McCance & Widdowson 2015, *Linwood’s product information for shelled hemp

The road forward
Heated debates around dietary choices occur on a daily basis on social media, the leading information hub in today’s frantic pace of life. Guidelines are being challenged by academics and ordinary folk alike leaving great confusion in their wake. The irrefutable argument remains that careful consideration of macronutrient intake need to be considered when food substitution is implemented, be it for moral, religious, or medical reasons. The current food revolution is still in its infancy and sound data will only be available in a few decades’ time. Avoiding exposure to food borne pathogens that cause gastrointestinal upset is sound advice. However, implementing food substitution without careful consideration in terms of overall nutrient status is naive and potentially damaging. We are living longer than our distant ancestors and as a result need to fuel ourselves such that we can enjoy life to the fullest rather than spending our golden years in hospital queues and swallowing handfuls of medication.

Alpro® (2018) ‘Alpro® Drinks’, available at, accessed on 12/4/18

British Nutrition Foundation (BNF) (2016) ‘Nutrition Requirements’, available at, accessed on 18/4/18

Centre for Disease Control and Prevention (CDC) (2018), ‘Reports of Selected Salmonella Outbreak Investigations’, available at, accessed 18/4/18

Lean, M.E.J., Astrup, A., and Roberts, S.B. (2018), ‘Making progress on the global crisis of obesity and weight management’, BMJ, Science and Politics of Nutrition, Vol. 306, pp. 1-7, available at, accessed 26/6/18

Linwoods (2018) ‘Product information for shelled hemp’, available at, accessed 7/6/18

Public Health England (PHE) (2018) ‘PHE launches Change4Life campaign around children’s snacking’, available at, accessed 12/4/18

Quorn™ (2018) ‘Quorn™ mince product information’, available at, accessed 12/4/18

Reuters/ABC (2018) ‘South African listeria outbreak largest on record WHO says as government blames food firms’, available at, accessed 15/3/18

WHO (2018) ‘Listeria infections’, available at, accessed 16/3/18

Wholefoods Online (2018), ‘Textured Vegetable Protein Savoury Mince (TVP) product information’, available at, accessed on 12/4/18