Numerous studies have shown that lowering your caloric intake may slow down aging, reduce age-related chronic diseases and extend lifespan. The effects have been observed in a variety of species from worms and yeast to rats and fish, and there’s evidence that it has a similar effect on the human lifespan.

However, when digging deeper, it seems clear that the underlying factor that makes calorie restriction beneficial in the first place, is the lowering of insulin levels.

What we now know about calorie restriction is that it reduces metabolic rate and oxidative stress, and alters neuroendocrine and sympathetic nervous system function in animals, as noted in a 2003 review in the American Journal of Clinical Nutrition.

It also improves insulin sensitivity, and this factor may explain much of the longevity phenomenon, as again evidenced by the results in this latest study.

This all makes perfect sense since we also know that high insulin levels speeds up the aging process.

Reducing Sugar Consumption Can Add Years to Your Life

I do believe that eating less is likely to be healthier for most people in the long run, but even more important is eating foods and drinking beverages that do not excessively raise your insulin levels.

Eating sugar and grains, for example, increase your insulin level and is a sure way to accelerate the aging process. Beverages play a paramount role here, as high fructose corn syrup from soda is the number one source of calories in the US. and devastates your insulin resistance.

Diets high in sugar and grains are also the primary culprit of obesity, and leanness, more so than food restriction in general, is also a key contributor to a long life, as evidenced by another 2003 study published in the journal Science. This elegant study from Harvard also confirms that insulin is the major mechanism through which this result is mediated.

Unfortunately, many health care practitioners are still ignorant of the profound influence that insulin has on health. Please understand that a firm appreciation of insulin’s role is one of the most important things you can do to optimize your health and outlive the naysayers.

For an excellent, in-depth review of just how damaging sugar (especially fructose) is to your health, please watch this lecture by Dr. Lustig if you haven’t done so already. It’s a shocking eye-opener that explains the many intricacies of how sugar impacts your health.

It Is Not Just ‘How Much,’ But Rather ‘What’ You Eat Determines Your Longevity

The authors of the study above state:

“Interestingly, centenarians have lower blood glucose, insulin, leptin, free T₃ and serum triglycerides than those who do not live to be over one hundred years old. Therefore, the fundamental mechanism by which calorie restriction improves lifespan appears to alter these metabolic parameters.

In this paper, we examine the impact of a diet specifically designed to improve metabolic parameters independent of caloric intake.

The diet is based on the premise that by reducing glucose and protein as substrates for oxidative metabolism and enhancing fatty acid oxidation, many of the same physiologic changes that are seen in calorie-restricted animals will also be seen in individuals following this type of diet.”

One key factor here, that I find interesting, is the fact that they’re not focusing on caloric intake at all. The amount of food is not restricted, but rather participants were told to let hunger dictate. Instead, the researchers focused in on the type of foods that will result in lowered blood glucose, insulin, leptin and triglycerides – all important factors in overall health.

So, what are these foods?

Foods that Might Let You Live to See Your 100^th Birthday

Here’s where it gets really interesting, because contrary to popular dietary advice, one of the primary keys here is the elimination of starchy carbohydrates. In addition, the diet included “unlimited amounts of certain fats and oils,” such as:

• Raw nuts and seeds
• Avocados
• Olives
• Olive oil

Participants that did not exercise limited their protein intake to approximately 1 gram per kilo of body mass per day, while those who exercised were allowed 1.25 grams/kg of body weight per day. (This equated to 50-80 grams of protein per day for most participants.)

Sources of protein included:

• Fish, sardines, and other seafood
• Eggs
• Tofu
• Chicken and turkey
• Wild game
• Cheeses like cottage cheese, ricotta and Swiss
• Veggie burgers

As for carbohydrates, only non-starchy, fibrous vegetables were allowed, such as:

• Lettuce and other greens
• Broccoli and cauliflower
• Cucumbers
• Mushrooms
• Onions
• Peppers
• Sprouts
• Asparagus
• Seaweed

Most of the participants ended up eating a diet consisting of 20 percent (non-starchy) carbs, 20 percent protein, and 60 percent fat, and as a result the participants lost an average of about 7 pounds over the course of about three months.

Now, I have to add that although this ratio of carbs/protein/fat did cause significant weight loss for the participants in this study group, it may or may not be the ideal ratio for everyone, especially long-term. We’re all different, and depending on your nutritional type, you may need more or less of each of these three types of nutrients. Additionally, some of the sources of protein on this list could do more harm than good.

For more information about nutritional typing and developing an individualized dietary plan, please refer to my free optimized nutrition plan.

However, the main point here is that the elimination of starchy carbs (grains) led to significant health benefits for all participants.

In addition to the above dietary recommendations, participants were also instructed to limit their beverages to 6-8 eight ounce glasses of water and/or herbal tea -- again, completely eliminating sugary drinks like sodas and fruit juices.

Nutritional supplements “to support fat metabolism and enhance insulin sensitivity” were also recommended, including:

• L-carnitine 2000 mg
• Alpha-lipoic acid 400 mg
• CoQ10 100 mg
• Cod liver oil 1tbsp
• Magnesium 300 mg
• Vitamin C 1000 mg
• Vitamin E 800 mg
• Multivitamin that included all essential B vitamins and minerals

Last, but certainly not least, lipid-lowering or sulfonylurea medications were discontinued before starting the diet, and those taking blood pressure medications had their dosages reduced or discontinued once their blood pressure normalized.

Now, in addition to significant weight loss, the participants also saw significant improvements in all the areas that impact longevity, including:

• Reduced systolic and diastolic blood pressure (by about 10 and 11 mmHg, respectively)
• Reduced leptin levels (by about 48 percent)
• Reduced insulin levels (by about 40 percent)
• Reduced fasting glucose levels (by about 7 percent)
• Reduced free T₃ (by about 10 percent)
• Reduced triglyceride levels (by 28 percent)

The average triglyceride/HDL ratio (a potent heart disease predictor) also decreased by approximately 50 percent!

The authors concluded that “in the context of an outpatient medical clinic, a high-fat, adequate-protein, low-carbohydrate diet with nutritional supplementation led to improvements in serum factors related to the aging process.”

No kidding!

I can’t think of any drug that can boast beneficial health results like these.

Leptin – As Important as Insulin for Health and Longevity

Of particular note is the fact that the above diet was able to reduce leptin levels by a healthy 48 percent in about three months! Because there’s evidence that leptin could possibly be even more important a factor for optimizing your health and increasing your lifespan.

Just like insulin, the hormone leptin has also been implicated in a vast number of chronic diseases that are typically associated with the aging process. Leptin is produced by your fat cells, and tells your body whether more energy is needed (thereby controlling your appetite) and what to do with the energy available.

Leptin also largely influences, if not controls, the functions of the hypothalamus in your brain, which impacts your:

• Reproduction
• Thyroid function
• Adrenal function
• Sympathetic nervous system

So just like your insulin levels, if your leptin levels become elevated, your body systems will develop a resistance to this hormone, which will wreak havoc in your body.

Final Thoughts

The study above is a beautiful illustration of how you can significantly improve your health and extend your life by eliminating sugar and starchy carbs, and eating a diet high in healthy fats, fresh veggies and lean proteins – all in as little as THREE MONTHS!

No meds required.

How wonderful is that?!

So, what are you waiting for?