On the journey to lose weight there are so many theories out there that people do not know where to start. Do I cut out all carbs? Do I run 4 miles a day or is strength training better? Do I eat only 1000 calories per day? For the most part I see people chose to drastically cut calories and/or try to cut out ALL carbs. In the short term, weight loss is rapid. In the long term, these people tend to gain the weight back, if not more, and find themselves to be low energy and sometimes even grumpy. Below Allison Aubrey from National Public Radio explains to us why our body's hunger gauge may be off when such drastic measures are taken.

By Allison Aubrey, From National Public Radio

There are some fresh insights from Australia that help explain why it's so difficult for dieters to keep off the weight they lose.

Willpower will only take you so far, in case you haven't run that experiment yourself. Turns out our bodies have a fuel gauge, not entirely unlike the gas gauge on our cars, that tell us when it's time to tank up on food.

The gauge relies on hormones that signal to the brain when and how much to eat. But as Dr. Louis Aronne, who directs the comprehensive weight control program at Weill Cornell Medical College in New York, explains, the human fuel gauge can sometimes be way off the mark — especially for dieters.

A study just published in the New England Journal of Medicine documents a pretty extreme diet regimen that limited 50 overweight and obese Australian volunteers to about 550 calories a day for 10 weeks.

Most of them, though not all, actually stuck with the diet, and, not surprisingly, lost a lot of weight. While dieting they shed an average of nearly 30 pounds, or 14 percent of their body weight. At a year, they'd still kept a lot of the weight off, but, on average, their loss was down to 8 percent 15 months after the start of the study.

What happened to their hormones? The researchers measured a whole bunch of them, including insulin, leptin (an appetite suppressant) and ghrelin (a hunger stimulator) and found that more than year after the weight loss, the hormones were telling the people to keep eating — a lot.

As Aronne puts it, their internal gas gauges went down 65 percent instead of the 10 percent or so that would have been more in line with the weight lost. In essence, "they think they're going to run out of gas very, very soon."

So it's not just a lack of willpower that's tripping people up. Their hormones are sending a strong, confounding signal to chow down.

What's more, the study found that the metabolic rate of the dieters remained low a year after the low-calorie diet ended, making it even harder to burn off those calories.

For more details on the story visit NPR's Health Blog.

About Allison Aubrey

Allison Aubrey is a correspondent for NPR News.

Focusing on stories related to food, nutrition, and health, Aubrey's stories can be heard on NPR's newsmagazines including Morning Editionand All Things Considered. She is the host of the NPR video series Tiny Desk Kitchen and contributes to Shots, NPR's health blog.

Through her reporting Aubrey can focus on her curiosities about food and culture. She has investigated the nutritional, and taste, differences between grass fed and corn feed beef. Aubrey looked into the hype behind the claims of antioxidants in berries and the claim that honey is a cure-all for allergies.