Читать книгу The Sirt Diet Cookbook - Jacqueline Whitehart, Jacqueline Whitehart - Страница 8

SIRT foods are super antioxidants that activate the sirtuin genes in our body, producing an increased fat-burning response. In a nutshell, eating more of these foods will boost your metabolism and help you lose weight faster.

THE SIRTUIN GENES

There are seven sirtuin genes in humans, imaginatively named SIRT1 to SIRT7. Geneticists have done several studies on the sirtuins and have had positive results relating to increased lifespan, metabolism and anti-ageing. Scientists are only just beginning to understand the function of individual genes and there is a lot still to be done, particularly related to how the genes work together.

SIRT1, SIRT3 and SIRT4 function predominantly on the metabolism, with SIRT4 specifically related to insulin sensitivity. SIRT2, SIRT6 and SIRT7 have more anti-ageing tasks related to cell and DNA repair. The individual genes do not work in isolation, but in combination, in ways that we do not yet fully understand. What is abundantly clear is that the sirtuin family of genes are extremely valuable within the body and activating these genes makes us healthier, promotes weight-loss and helps us age gracefully. So how do we go about making these genes work better?

It has recently been established that there are two main triggers for the sirtuin genes. One is calorie restriction and the other is SIRT activators. Foods that contain a rich source of SIRT activators are collectively called SIRT foods.

Perhaps you’ve tried calorie restriction, fasting or the 5:2 Diet? They definitely work and can produce dramatic results but you need a lot of willpower to stick to the diets over the long term. What if there is an alternative, where you substitute special foods for fasting or calorie restriction? Not only that, but these special foods are easy to come by and are tasty, flavoursome and wholesome.

With a SIRT-rich diet, your genes benefit in a very similar way to calorie restriction … without restricting calories.

SIRTUINS AND YOUR HEALTH

When you activate the SIRT proteins in your body, they act as ‘housekeepers’ doing all the hard work that other genes don’t or can’t do. Sirtuins are a family of age-related proteins. The main role of sirtuins is to selectively regulate the activity of key genes responsible for metabolism and cell defence:

1 Increase fat metabolism, burning more calories from fat

It has been shown that SIRT activation shifts metabolism away from using glucose as an energy source, favouring fat synthesis.

2 Reduce insulin response

The hormone Insulin-like Growth Factor 1 (IGF-1) is proven to decrease as SIRT genes are activated. IGF-1 is produced in the liver and is similar to insulin. Its purpose in the body is to make cells grow and produce new cells. When levels of IGF-1 decrease, our body produces few new cells and concentrates on repairing old ones. This state of ‘repair’ is very beneficial as it slows down the ageing process.

3 Fight inflammation

Through their powerful antioxidant effect, sirtuins reduce oxidative stress, which has positive repercussions for cardiovascular protection and heart health.

HOW DO SIRTUINS HELP YOU LOSE WEIGHT?

Triggering your SIRT genes sparks a change in your meta-

bolism that breaks down more fat cells. The activated SIRTs increase the amount of a neurotransmitter called norepinephrine, which is used by the nervous system as a signal to fat cells, telling them to break down fat. The signal telling the fat cell to convert fat to energy is stronger, increasing fat burning.

Want to burn more fat?

Drink green tea. Green tea combines SIRT activators and a (small) dose of caffeine. The caffeine enhances the effect of the SIRTs, meaning more fat is broken down.

Natural appetite suppressant effect

When the body breaks down fat, the fat is converted into energy. This energy is used immediately by the body. This has a positive effect on how you feel, giving your energy levels a boost and decreasing hunger.

Converting fat to muscle

Combining SIRTs with exercise boosts the fat-burning effect even further. If you exercise the energy released from fat cells is available for strengthening muscles.

In practice this means that if you follow the SIRT diet and exercise several times a week you will not only lose weight, but you will look and feel leaner as some of the weight has been converted into muscle.

For absolute peak fat-burning performance when exercising, drink two cups of green tea (for the SIRTs and the caffeine) within one hour before or after exercise.