''The Hacker's Diet'' (humorously subtitled "''How to lose weight and hair through stress and poor nutrition''") is a

diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...

plan created by the founder of

Autodesk Autodesk, Inc. is an American multinational software corporation that provides software products and services for the architecture, engineering, construction, manufacturing, media, education, and entertainment industries. Autodesk is headquarte ...

, John Walker, outlined in an

electronic book An ebook (short for electronic book), also spelled as e-book or eBook, is a book publication made available in electronic form, consisting of text, images, or both, readable on the flat-panel display of computers or other electronic devices. A ...

of the same name, that attempts to aid the process of

weight loss Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat (adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other conn ...

by more accurately modeling how

calorie The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, kilocalorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter o ...

s consumed and calories expended actually impact weight. Walker notes that much of our fat free mass introduces

signal noise In electronics, noise is an unwanted disturbance in an electrical signal. Noise generated by electronic devices varies greatly as it is produced by several different effects. In particular, noise is inherent in physics and central to thermod ...

when trying to determine how much weight we're actually losing or gaining. With the help of a graphing tool ( Excel is used in the book), he addresses these problems. Factoring in

exercise Exercise or workout is physical activity that enhances or maintains fitness and overall health. It is performed for various reasons, including weight loss or maintenance, to aid growth and improve strength, develop muscles and the cardio ...

, and through counting calories, one can calculate one's own total energy expenditure (

basal metabolic rate Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest.. In other words it is the energy required by body organs to perform normal It is reported in energy units per unit time ranging from watt ( ...

thermic effect of food Specific dynamic action (SDA), also known as thermic effect of food (TEF) or dietary induced thermogenesis (DIT), is the amount of energy expenditure above the basal metabolic rate due to the cost of processing food for use and storage. Heat produ ...

, and day-to-day exercise) and cut back calorie intake or increase exercise to lose weight.

Dieting as an engineering problem

Walker describes the diet as approaching weight loss "as an

engineering Engineering is the practice of using natural science, mathematics, and the engineering design process to Problem solving#Engineering, solve problems within technology, increase efficiency and productivity, and improve Systems engineering, s ...

problem", claiming that his approach enabled him to reduce his weight from 98 kg to 66 kg in a year and keep it stable afterwards. Walker considers the problem of weight loss and maintenance as a

control system A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial ...

problem. Simplifying the problem to the barest elements, he models the human body as a "rubber bag," where variables such as food type, frequency, metabolic rates and even exercise are considered negligible. According to Walker, the difference between calorie intake and expenditure is the key (a calorie surplus leads to weight gain; a calorie deficit leads to weight loss). To solve the problem, one needs to monitor calorie intake and weight loss rate and make the desired proportional adjustments to reach the desired goal.

The body as a system

Walker also introduces the reader at some length to simple

feedback Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause and effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handle ...

and

s, providing spreadsheets to demonstrate feedback, oscillation and data smoothing to illustrate his arguments. While the diet is a fairly straightforward

-counting approach, data smoothing ( exponential moving averages in particular) is considered a key element of the monitoring system. Walker presents techniques for Excel-aided or paper-and-pencil data smoothing to allow the dieter to adjust the diet for themselves using the long-term trend and to not be discouraged by short-term fluctuations based on water retention or other factors. The diet also uses the trend line as a control system to allow the dieter early warning of relapse after the target weight is reached. As Walker states, "The vast majority of people who lose weight end up, in relatively short order, gaining back every pound they lost." A quick check of the trend line provides an easy way to make small adjustments in intake, allowing much greater control of weight for life.

Tools

Walker uses Excel spreadsheets to log weight and produce charts but provides a list of other software packages that may be used. Walker also provides a free online tracker and grapher at his Fourmilab website, and the program Eat Watch, mobile tracking and charting services for the Palm platform.

References

External links

The Hacker's Diet

OpenOffice.org-compatible Hacker's Diet spreadsheet tools
{{DEFAULTSORT:Hackers Diet Autodesk Diets

Dieting as an engineering problem

The body as a system

Tools

See also

References

External links