Alternate Day Dieting

There’s a simple way to extend lifespan by 25% and that’s to eat a diet that’s very low calories. It’s well proven in all animal species but is unlikely to catch on in us humans.

However, thanks to the work of Professor Mark Mattson from the US National Institute on Ageing, he discovered that you can get an equivalent effect, and many other health benefits, by modified fasting two days a week, or eating less every other day. The benefits appear to be many – less pain and inflammation, less risk for diabetes and possibly dementia and, of course, less weight.

This way of eating, known as alternate day dieting, seems to work because it can trigger the health-promoting gene called ‘Sweet Sixteen’. You may recall, last year, a study that showed that eating low calories for eight weeks reversed diabetes, improving sensitivity to the hormone insulin.

Insulin seems to be the key – the less you produce the better. A recent study of 64,000 people with diabetes, reported last month at the American College of Cardiology, well illustrates this point. The researchers found that the more insulin medication a person uses, the greater their risk for a cardiovascular event (death, heart attack or stroke).

To put this into context, a diabetic using insulin has a 70% increased risk of a first cardiovascular event compared to someone who already has cardiovascular disease having another event. The more insulin resistant a person is, the more insulin they are given. (By the way, the only drug that also helps reverse insulin resistance is metformin, which is the only diabetes drug in this study that didn’t increase cardiovascular risk.)

What this recent research shows is that too much insulin switches on a diabetes and heart disease promoting gene, nicknamed the Grim Reaper. Clearly this is not the right way to go. What you want to do is improve insulin sensitivity, and to eat in a way that means you need less insulin anyway. The best way to do that, according to gene expert Professor Cynthia Kenyon from the University of California, is to eat a low glycemic load (GL) diet, cutting right back on carbohydrates which promote insulin release. Supplementing high-dose chromium (200-600mcg), even better with a cinnamon extract high in the compound MCHP, also helps reverse insulin resistance by improving the function of insulin receptors.

This is the kind of diet I’ve been recommending for years because it has so many health benefits besides rapid weight loss. Some low GL approaches, such as Atkins and Dukan diets, are based on avoiding carbs, and increasing high-protein foods. I’m not a fan of this approach long-term – although it can kick start the process of recovery or weight loss in the short-term – because you end up on a diet high in meat and dairy products, which is a recipe for increasing cancer risk.

Also, dairy products, while low in sugar, do promote insulin hormones, which is what you want to avoid. There are other downsides too is relation to bone density and kidney function, which is already impaired in many people with diabetes and cardiovascular disease.

My preferred low GL diet approach means eating less carbs rather than no carbs at all, but always choosing ones that release their sugar content slowly. Berries, cherries and plums, for example, have very slow-releasing sugars. Increasing antioxidants from fruit and vegetables also makes sense from an anti-ageing point of view.

The idea of eating less every other day, or having two or three very low-calorie days, makes a lot of sense from an evolutionary perspective. After all, our hunter-gatherer ancestors would have had lean days and feast days on a regular basis.

Kick-starting your anti-ageing genes In order to trigger this change in genetic expression – and switch on your anti-aging Sweet Sixteen gene – it seems, judging by animal studies, you need four weeks of eating less every other day, with at least a 20% difference in calorie intake between your feast and fast days. If the same applies to us, and if you are controlling the GL of your diet, and hence insulin release (which is recommended), then this would be equivalent to eating 60 GLs on the feast day and 45 GLs on the fast day. Or if you want to lose weight as well, 50 GLs on the feast day and 40 GLs on the fast day.

The Low GL Diet Bible and the Low GL Diet Cookbook explain how to do this. It is best to get well established on a low GL diet, helping to break carb addiction, before going one step further into alternate day dieting. My GL diet is based on 45 GLs a day to lose weight and 60 GLs to maintain it. The books give you examples, daily menus and recipes of what 40 GLs and 60 GLs means in terms of food. 5 GLs is the daily allowance for drinks or desserts. So, a simple way to do a ‘lean’ day is not to have any GL containing drinks (eg juices etc), having water and teas instead.

How to fast twice a week After the first four weeks, you can switch to two days eating normally, followed by one day eating no more than 500–800 calories, then back to two days eating normally and so on. By eating normally, I mean enjoying a low-GL, highly nutritious diet. I gave you a number of options for achieving this in issue 65 last year.

Are you on the right track? Since the holy grail of anti-ageing is to keep your insulin levels down, the best way to monitor that you are on the right track is to measure your insulin levels. However, this is not that straightforward, so an easier alternative is to measure your glycosylated haemoglobin (HbA1c). What this shows is the percentage of sugar-coated (glycosylated) red blood cells (haemoglobin) you have. This occurs each time your blood sugar levels go high – which also promotes more insulin to be released. So the more often you experience blood sugar peaks, the more red blood cells become sugar coated. And you can measure this via a pin prick test, available using a home kit. You are on the right track if your score is less than 5.5% or even better, below 5%. Above 7% means diabetes.