Food choices are so important in determining lifespan and quality of life.
Genetics perhaps determine about 20% of a person's health outcomes, and environment, including food choices, determine about 80%. This can be seen at a population level in the so called Blue Zones (1), which are areas of extended life span and health.
Main Ideas
For optimising health and longevity, try to choose a pattern of eating, by choosing foods that together are:
High in fibre
Low in saturated fat
High in polyunsaturated fat
Protein that in predominantly or exclusively from plant sources
Low in ultra-processed foods (UPF)
In our community
Fibre is found in all plant foods such as vegetables, fruit, whole grains (such as whole wheat, oats, brown or wild rice, corn, quinoa and barley), lentils and legumes (green beans and peas and pulses), nuts and seeds.
Saturated fats are most concentrated in some processed foods, including processed meats, and red meat, poultry and dairy. They also are in tropical oils such as coconut and palm oil.
Unsaturated fats are in the most concentrated forms are sourced from fish and plant foods such as nuts, seeds, avocado, and olives. They can be found in olive oil and canola oil which are the cooking oils I most often recommend.
Plant sources of protein include whole grains, lentils and legumes, nuts and seeds.
UPF are consumed at a high level. Think of the rows of packets and containers of food in the supermarket. These foods have highly refined ingredients and tend to be low in fibre, high in unhealthy fats, low in protein, low in nutrients, and are hyperpalatable and highly addictive. They have usually been constructed by food scientists to make them irresistible.
What else about protein?
Plant protein is as good a source of animo acids as animal protein. All plants contain all essential amino acids (those our bodies cannot make). Plant sources may be inadequate in providing adequate amino acids if there is not a range of foods eaten. For example, relying on only brown rice for protein. If another source was added, such as from vegetables or legumes, a complete source is expected.
Bioavailability of amino acids. If food is properly prepared and adequate protein is consumed from plant sources, muscle synthesis is as good. This has been well researched over the last years.
Animal sources of protein are more likely to come with saturated fats. This is because most of the meat sources we buy are farmed and not sourced from game such as wild venison or bush meat from hunting. Swapping protein to plant sources has been shown to improve healthy aging, not have negative physical or mental health sequalae, and reduce the risk of chronic disease such as cardiovascular disease, kidney disease, lung disease and neurogenerative diseases. (2)
How much protein? I would recommend 1.5-1.6g of protein per kg of body weight for athletes and those training for strength or muscle performance. For most other people, 1.2g/ kg is very good. This includes older people who are at risk of frailty if protein intake is not adequate. I use Cronometer, an app to measure protein (or other nutrient quantities)
Note that muscles do not become stronger by eating more protein. They require stimulus with training.
Cholesterol, in particular LDL cholesterol, non-HDL cholesterol or apolipoprotein B, is a biomarker for the risk of developing atherosclerotic vascular diseases such as heart disease, stroke, and dementia. There is good research showing that red and white meat increase LDL cholesterol, and plant proteins do not.
The Portfolio diet (3) is a collection of a few plant foods that use different mechanisms to collectively reduce cholesterol levels (statistical equivalence to a low dose statin medication). The components used in the study were plant sterols (plant sterol enriched margerine), soybeans (eg soy milk, tofu, edamame and soy meat analogues), viscous fibres (eg oats, barley and psyllium) and nuts. They demonstrated a 13% reduction in LDL, which translates to over 11% reduction in cardiovascular risk.
Protein intake is optimised if taken in amounts across the day rather than when concentrated in one meal.
See appendix for sources of protein.
What else about fats?
Swapping saturated fat for polyunsaturated fat reduces the risk of a cardiovascular event by a significant amount. Long-term observation studies show this and are in -line with government food guidelines.
Linoleic acid is a common unsaturated omega-6 fat found in seed oils. People consuming more of these foods have less heart disease.
It is also important to remember that all oils and fats are equally high in calories. For those trying to lose weight, reducing total fat intake is an important strategy. Better sources of plant oils are high fibre sources such as nuts and seeds which are inefficiently absorbed from the gut.
Animal foods contain cholesterol. This is not thought to be as concerning as the amount of saturated fat but it is still recommended to limit cholesterol intake.
What else about fibre?
Perhaps the biggest fault in our community is the lack of fibre in our diet.
Fibre reduces transit time in the colon which means that our bowel habits are more regular and reduces the effect of carcinogenic compounds in the colon.
Fibre is the principal food supply for our microbiome, which is the trillions of microbes that live in our guts. The microbiome is incredibly important for our health, and has been shown to affect so many different functions in our body. We have evolved with these microbes in a symbiotic relationship and have outsourced the digestion of complex carbohydrates (fibre) to them, and in return receive the metabolites which include short chain fatty acids. One of these is butyrate which provides a large proportion of the nutrients to our colon cells and is positively influential for our immune function. It has an anti-inflammatory effect in the body, reduces colonic inflammatory conditions by maintaining the junctions between cells (and avoiding leaky gut), reduces bowel cancer risk, improves the metabolism of glucose with improved insulin sensitivity, and is thought to be good for improving brain neuroplasticity and sleep quality.
Fibre slows down the absorption of nutrients in the blood including glucose which reduces the spike in blood glucose levels.
GLP1 is a hormone that our body makes. One of its effects is to reduce appetite. It has become better known with the publicity around Ozempic, a medication to lose weight. Consumption of fibre stimulates GLP1, thereby improving satiety.
If you are trying to increase the amount of fibre in your diet, it may be best to increase slowly as the microbiome may not be “ready” and the effect may be to cause bloating, cramping and gas. Including fermented foods in your diet, such as sauerkraut, yogurt or kimchi has been shown to be helpful. Having some resistant starch can be a good way of increasing fibre early or to avoid unpleasant symptoms. This can be made by cooking a starchy food such as potato or rice, letting it cool, and later reheating and consuming.
Increasing the variety of plant fibres, and including herbs and spices is a good goal. Simon Hill from The Proof podcast (4) has a practical way of looking at this. He talks about keeping a diary of different plant foods over a week and trying to increase the number to 30.
If you get unpleasant symptoms with fibre, it may be that your microbiome is not very healthy. This could be due to not eating much fibre over the years, having lots of antibiotics, having an inflammatory bowel condition or even being born by Caesarian Section.
How to start?
If you are starting from scratch, try to first reduce or eliminate ultra- processed foods. It is important to note that changing from saturated fats to highly refined carbohydrates (such as white flour products or white rice) are not likely to be beneficial.
A Mediterranean style diet has been associated with good health outcomes. This is a predominant unprocessed plant food diet (supplying >80% of total calories), and if you are having animal protein, then oily fish, eggs or a fermented dairy food such as natural or Greek yogurt or some cheese would be preferable. The Danish Food Guidelines, one of the more recently published guidelines, take this position of plant dominant diet.
See appendix for some starter recipe ideas.
It is hard to argue for a plant exclusive or vegan diet for health reasons. Most of the benefits of having so many plant foods will be seen when they add to more than 80% of the total food intake. I would suggest that ethical arguments around the environment or the treatment of animals remain the best arguments for a plant exclusive diet.
The health of the planet. I like to think that this is important to consider. About 80% of the land that we use to grow food is for growing animal foods which only supplies less than 20% of our calories (energy). This is an inefficient use of a large amount of land. This results in deforestation, loss of wildlife and biodiversity, increased water consumption, overuse of fertilisers, and increased greenhouse gases. "Food is the strongest lever to optimise human health and environmental sustainability on earth". (5)
To eat a nutrient balanced plant exclusive diet, it is necessary to have to have some information to achieve a healthy diet, to have access to a diversity of plant foods, and to store and cook these foods, knowing tasty recipes. Otherwise, it might be wise to achieve a high level of plant foods and to reduce the risk of having an unbalanced diet by including some animal foods as stated above.
A word on diabetes
Type 2 diabetes is a reversible condition if recognised early before the pancreas is damaged. It is a disease of caloric excess. It does not seem to be related to body weight in a linear way but rather depends on the distribution of body fat. Those who store more fat in the subcutaneous tissues are not as affected as those who store fat around the middle, including visceral fat (fat in and around our abdominal organs). We know that the excess stores of fat in the liver and pancreas lead to increased blood glucose levels, which increases blood insulin levels. Over time this creates insulin resistance, which is fat cells not responding to insulin to take in glucose from the blood. The increasing insulin levels result in damaged beta cells in the pancreas, which further accents the inability to reduce blood glucose levels in a spiraling fashion. High glucose leads to increased inflammation which has negative effects including more pain in osteoarthritis and worsening cardiovascular disease and cognitive decline.
Research (6) shows reversibility using caloric reduction, with meal replacement shakes, then transition to low calorie diet, and the Mastering Diabetes (7) outfit in US have had great success with whole food plant-based diets.
Saturated fat in the diet will increase the fat in the liver, whereas unsaturated fats do not increase fat storage in the liver.
It is also important to state that exercise will improve insulin sensitivity by consuming and lowering blood glucose without involving insulin.
Some facts about how Ultra processed Foods (UPF) affect our bodies (8)
The destruction of the food matrix means that UPF is generally soft. This means that you eat it fast and eat far more calories quickly and don’t feel full until long after you have finished it.
UPF typically has very high calorie density because it is dry, high in fat and sugar and low in fibre so you get more calories per mouthful.
It displaces diverse whole foods from the diet. It is usually micro-nutrient deficient.
The mismatch between the taste signals from the mouth and the nutrition content in some UPF alters metabolism and appetite.
UPF is addictive, which makes bingeing more likely.
The emulsifiers, preservatives, modified starches and other additives damage the microbiome, which could allow inflammatory microbes to flourish and damage the gut lining.
The convenience, price and marketing of UPF urge us to eat constantly, and without thought, which leads to more snacking, less chewing, faster eating, increased consumption and more tooth decay.
The additives and physical processing mean that UPF affects our satiety directly. Other additives may affect brain and endocrine functioning.
The production methods used to make UPF require expensive subsidy and drive environmental destruction, carbon emissions and plastic pollution which harms us all.
Appendix
Sources of Protein
Large egg 6.3g protein
1 medium slice wholemeal bread (36g) 17.9g protein
1 cup oats 5.3g protein
1 tablespoon pepitas 2.2g protein
1 tablespoon peanut butter 3.9g protein
1 tablespoon of almonds 1.7g protein
Chickpeas cooked (100g) 7.05g protein
Black beans cooked (100g) 8.86g protein
Lentils cooked (1/2 cup= 100g) 9.02g protein
Broccholi cooked (1 cup) 2.4g protein
Cheddar cheese (17g=1 slice) 3.96g protein
Greek yogurt (200g) 19.9g protein
Milk (1 cup) 8.32g protein
Some starter recipes
Bolognese sauce/Taco filling
Replace some of the mincemeat with lentils for Bolognese, and with black or kidney beans for taco filling. These legumes will absorb taste and texturally will go well with mincemeat. Braise the meat with onion and garlic and include other finely chopped vegetables and herbs in the sauces. Over time replace more of the meat with the legumes to increase the nutritional value.
Stir fry
Have an abundance of vegetables, with either no meat or small shreds of meat for flavour, which is best braised early with onion, garlic or ginger. Mushrooms can be used as a meat texture substitute. Tofu or nuts are good sources of protein. Best served with brown rice.
Porridge or muesli are excellent breakfast ideas, or overnight oats. Adding fresh or dried fruit improves the nutritional value further.
Smoothies are an excellent way of including a variety of fruit, oats, seeds and even spinach. Consider a plant-based milk, and some frozen fruit for a chill factor.
Wholemeal wraps filled with grated or chopped salad vegetables. Consider avocado or hummus instead of butter or cheese.
Doctors For Nutrition website has a large number of healthy whole food plant-based recipes and how to get started cooking more plant foods.
References
1 Blue Zones see book by Dan Buettner (also is a Netflix series, which I haven't watched!)
2 Dietary protein intake in midlife in relation to healthy aging- results from the prospective
Nurses Health Study cohort. Andres V Ardisson Korat et al. Am J Clin Nutr. 2024 Feb
3 The Proof with Simon Hill. A podcast with well communicated information on health, especially nutrition.
4 Summary report of the EAT Lancet Commission
5 Nutritional basis of type 2 diabetes remission. Roy Taylor, professor ,Ambady Ramachandran, professor, William S Yancy Jr, physician, Nita G Forouhi, professor. BMJ 2021; 374 doi 07 July 2021
6 Mastering diabetes https://www.masteringdiabetes.org
Additional reading
A very good published scientific article expanding on some of the big themes is;
Plant-based diets for personal, population, and planetary health. Hemler EC, Hu FB. Adv Nutr. (2019)
10:S275–s283. doi: 10.1093/advances/nmy117Swapping saturated fat for polyunsaturated fat reduces the risk of a cardiovascular event by a significant amount. Long-term observation studies show this and are in -line with government food guidelines.
Linoleic acid is a common unsaturated omega-6 fat found in seed oils. People consuming more of these foods have less heart disease.
It is also important to remember that all oils and fats are equally high in calories. For those trying to lose weight, reducing total fat intake is an important strategy. Better sources of plant oils are high fibre sources such as nuts and seeds which are inefficiently absorbed from the gut.
Animal foods contain cholesterol. This is not thought to be as concerning as the amount of saturated fat but it is still recommended to limit cholesterol intake.