The Harvard Plan: Is it really healthier than the Mediterranean Diet?

An extensive study has identified the diet that will help you live longest – and live healthiest.

Those who followed an eating plan devised by Harvard researchers known as the alternative healthy eating index (AHEI) improved their health and longevity the most.

Paleo, Atkins, the 5:2 – the average person tries (and abandons) countless diets over the course of their lifetime. Now a long-term study of more than 100,000 people over decades has identified the diet that can help you to live longest – and, crucially, to stay healthy as you do so.

It’s probably no surprise that in the US study the Mediterranean Diet and plant-based diets performed well, but it turns out that those who followed an eating plan devised by Harvard researchers known as the alternative healthy eating index (AHEI) improved their health and longevity the most. They reduced their risk of early death from cancer, neurodegenerative disease and heart disease.

Plant-based diets have never been so fashionable, and the benefits of Mediterranean-style eating are well known: it is rich in fruit, vegetables and olive oil and linked to decreased risk of heart disease, dementia and depression. By contrast, the less catchily named AHEI – let’s call it the Harvard Diet – hasn’t made many headlines since it was devised 21 years ago.

But the figures, published a few weeks ago in the Journal of the American Medical Association, speak for themselves: the study of 75,000 women and 44,000 men showed that those who stuck most closely to it reduced their overall risk of early death by up to 20 per cent (a greater reduction than the Mediterranean Diet).

The premise of the Harvard Diet is to forget talk of low-carb or calories and instead focus on eating a regular combination of high-quality foods.

Of course, adding years to your life is a boon only if those years are healthy ones. And a separate study published in the Journal of Nutrition showed that those who followed the Harvard Diet reduced their risk of developing type 2 diabetes by 33 per cent and coronary heart disease (which can increase the risk of stroke and dementia) by 31 per cent. Further studies on older people, published in the Journal of Nutrition and the Journal of Nutrition, Health and Ageing, found that those who followed it most closely stayed most active and mobile. All of which could add up to make it the healthiest diet the world has barely heard of.

Developed by Dr Walter Willett, chair of Harvard’s department of nutrition in 2002, the AHEI is a points-based scoring system that assigns ratings to foods and nutrients linked to your risk of developing chronic health conditions that affect almost more than half of over-60s. You get points for avoiding certain foods, as you do for eating more of others, so it’s as much about what you’re not eating. Consistency is rewarded – there are more points for eating a healthy food (or avoiding an unhealthy one) for a whole week. The results among those who follow the diet closely have been “remarkably consistent”, says Dr Frank Hu, who is now the department’s chair – not just in increasing lifespan but healthspan: how many of those years you remain healthy and disease-free.

The premise of the Harvard Diet is to forget talk of low-carb or calories and instead focus on eating a regular combination of high-quality foods. There is a series of non-negotiables: eating only wholegrains, such as brown rice and bulgur wheat, rather than refined kinds such as white bread or rice; choosing fish or plant-based proteins (such as tofu or chickpeas) over red meat; and picking unsaturated fats, such as peanut oil, nuts and avocados, over saturated ones (found in butter, cheese and palm oil).

The diet grades your nutrition, awarding a maximum of 10 points for seven factors. Although 70 would be a perfect score, most people score about 40 points. According to Hu, 56 reflects a healthy diet, and anything above that is gold standard. If you are scoring 30-40, or below, you need to look carefully at the categories you’re scoring badly in – are you eating too much red meat? Too few vegetables? – and increase or decrease your intake until your score starts rising.

You can gain points by eating certain foods more frequently, and you can increase your score by avoiding ‘bad’ foods.

I decided to see how my diet would fare under the scoring system, and was quietly confident I would do well. Given that I eat seafood at least twice a week and hoover up every bit of fruit and veg I can find, I assumed my score would be pretty high. But healthy habits are reliant on good routine, and when I totalled up my points for a particularly busy seven days last week, when I’d eaten a lot of high-convenience, low-nutrition foods, I got 45; less gold standard, more paltry bronze. This included a shameful nil points for wholegrains – I couldn’t remember the last time I’d eaten a serving.

I started the week with two helpings of kidney beans and planned to make sure that chickpeas, lentils and wholegrains made an appearance on my plate in some form every day for the rest of it. That, and returning to my usual red meat-free diet, should bring me up to the healthy 56 Hu suggests.

You can gain points by eating certain foods more frequently, and you can increase your score by avoiding “bad” foods. Red meat, for example, is to be largely avoided. Eating it every day would score you zero points, but you can score a respectable seven by eating it no more than four times across the week, and a perfect 10 if you don’t eat any at all.

Since this is the simplified version of a diet devised as a research tool for use by researchers and policymakers – and used complicated calculations of sodium and unhealthy saturated fats – not every area of dietary intake is scored. But the researchers advise that crisps, biscuits and cakes are off the table because of their high levels of fat and salt. As is sugar – even fruit juice is not allowed, because of its high sugar content.

Like me, many people will want to know about alcohol, which is not formally scored on the plan.

“Moderate drinking (no more than one drink a day for women and no more than two for men) has been associated with a lower risk of mortality, but the moderate alcohol recommendation is optional,” Hu says. “The key is to avoid excessive alcohol drinking. For those who don’t drink alcohol, there is no need to start. For those who drink more than a moderate amount of alcohol, they should cut it back.”

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Score your diet out of 70

70 points = perfect score

56 points = healthy diet

42 points = average, requires improvement. You probably need to eat more fruit, or reduce your red meat intake and eat nuts more often

20 or below = unhealthy diet

5 servings of vegetables a day = 10pts

1 serving = 250g green, leafy vegetables or 125g all other vegetables. Do not count white potatoes.

Score 2pts for each serving you eat each day (up to 5 servings). Add up your total for each day of the week and divide by 7 for your weekly score.

4 servings of whole fruit a day = 10pts

1 serving = 1 whole fruit or 125g berries. Do not count fruit juice.

Score 2.5pts for each serving you eat each day (up to 4 servings). Add up your total for each day of the week and divide by 7 for your weekly score.

5 servings of wholegrains a day = 10pts

1 serving = 125g wholegrain rice, bulgur, cereal or pasta, or 1 slice of non-white bread.

Score 2pts for each serving you eat each day (up to 5 servings). Add the total for each day of the week and divide by 7 for your weekly score.

Avoid all fruit juice and sugary drinks all week = 10pts

1 serving = 225ml fruit juice, sugary drink or sweetened tea/coffee.

Score 5pts for 3-4 servings per week (and a half serving per day); 0pts for 7 or more (1 serving per day).

7 servings of nuts, soy and beans a week = 10pts

1 serving = 28g nuts, 1 tbsp peanut butter, 125g beans, 100g tofu.

Score 5pts for 3-4 servings per week (and a half serving per day); 0pts for 0 servings.

Avoid red and processed meat all week = 10pts

1 serving = 42g processed meat (such as bacon) or 113g red meat (such as steak).

Score 7pts for 3-4 servings per week; 3pts for 7 servings.

2 servings of fish a week = 10pts

1 serving = 113g cooked fish or seafood.

Score 5pts for 1 serving per week; 0pts for 0 servings.

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