''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 makes software products and services for the architecture, engineering, construction, manufacturing, media, education, and entertainment industries. Autodesk is headquartered ...

, John Walker, outlined in an

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

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. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of on ...

s consumed and calories expended actually impact weight. Walker notes that much of our

fat free mass In physical fitness, body composition is used to describe the percentages of fat, bone, water, and muscle in human bodies. Because muscular Tissue (biology), tissue takes up less space in the body than fat tissue, body composition, as well as wei ...

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 the ...

when trying to determine how much weight we're actually losing or gaining. With the help of a graphing tool (

Excel ExCeL London (an abbreviation for Exhibition Centre London) is an exhibition centre, international convention centre and former hospital in the Custom House area of Newham, East London. It is situated on a site on the northern quay of the ...

is used in the book), he addresses these problems. Factoring in

exercise Exercise is a body activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons, to aid growth and improve strength, develop muscles and the cardiovascular system, hone athletic ...

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

basal metabolic rate Basal metabolic rate (BMR) is the rate of food energy, energy expenditure per unit time by endotherm, endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg b ...

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 produc ...

, 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 use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...

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 c ...

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 handled ...

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

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

''Healthy Food Choices for the Hacker's Diet Foods'' video
video exploring the pros and cons of the Hackers Diet {{DEFAULTSORT:Hackers Diet Autodesk Diets

Dieting as an engineering problem

The body as a system

Tools

See also

References

External links