1 Horsepower = 550 foot-lbs. of work per 1 second.

1 Calorie = The amount of heat required to raise one gram of water 1 degree Celcius or
1.8 degrees Fahrenheit.

1 Calorie = 4.184 Joules.

1 Joule = 1 newton times 1 meter, expressed in
newton-meters.

1 Newton = kilograms x 9.8 meters/sec squared.

Newton-Meters = Metric measurement for Work.

Foot-Lbs. = Standard measurement for Work.

Power = Force x Distance/Time; measured in Watts or Joules, depending on either Standard
or Metric applications.

BTU (British Thermal Unit) - The amount of
heat required to raise 1 lbs. of water by 1 degree Fahrenheit based on water's maximum density limit reached at 39.1 degrees F; Also a BTU can be used to define the difference in
temperature in water between 59 degree F and
60 degrees F; For approximation sakes, BTU is
defined as the amount of heat required to raise
one lbs. water 1 degree F.

1 BTU = 251.90 calories.

1 BTU = 1055 joules.

1 BTU = 778.26 foot-lbs.

Knowing this, in order to take the caloric potential energy found in a Twinkie at a stamped calorie count of let's say "300 calories", this means we have the following:

300 calories x 4.184 Joules = 1255.20 Joules.

1255.20 Joules / 1055 Joules = 1.19 BTU

1.19 BTU x 778.26 foot-lbs = 926.13 foot-lbs.

926.13 foot-lbs / 550 foot-lbs = 1.68

No units yet, because it is a coefficient
without any theoretical time limits presented.

However if placed over the span of one second
the theoretical HP would be 1.68 HP. This is
not practical, since the total energy release
of the twinky is unknown, and is specific to
each person's metabolic rate.

What is known, is that if in a controlled
environment and only that twinkie is being
assessed, and all energy is expended from that
twinkie of "300 calories", there would be an
approximate mechanical horsepower rating in
work performed per second of 1.68 HP, for that
given Twinkie.

The human body as you know is an internal
combustion heat engine as well. But based off
exothermic heat energy release through
chemical reactions.

But if you get into four and two stroke gasoline-powered piston engines, the formula
PLANK/33,000 foot-lbs per second can be used
to calculate the theoretical Horsepower Rating
of that given engine, based on specifications.
Indicated Horsepower (IHP) is all theoretical and does not factor in the Friction Horsepower
losses of the moving parts of the engine,
the load on the flywheel and the loads of the
application being driven by the engine. To
calculate the true Horsepower, IHP later has to
be derived to come up with Brake Horsepower
leading also to torque rating at a given RPM.

But for reference sakes, PLANK/33,000 foot-lbs./minute will allow you to calculate the Indicated Horsepower on a piston engine, which is defined as:

P = Mean Effective Internal Cylinder Pressure

L = Piston Stroke Length in feet.

A = Piston Surface Area (kept in square inches)

N = Number of Powerstrokes per minute; (on
four-stroke piston engine this would be
1/2 the RPM)

K = Number of cylinders.

33,000 foot-lbs/minute = 550 foot-lbs/sec times
60 seconds = Horsepower constant over 1 minute
since RPM is being used.

For calculating Theoretical Horsepower of a
given piston engine, also known as Indicated
Horsepower (IHP), an example will be given
below:

If you have a four-cycle, gasoline-driven,
eight cylinder, V8 automotive piston engine
with a Mean Effective Internal Cylinder Pressure of 195 PSI, bore/stroke of 3.25"/3.00" running at 2500 RPM, calculate the
IHP.

P = 195 PSI

L = 3/12 foot = 1/4 foot = 0.25 feet

A = Pi x (r)squared = 3.14159 x (1.625 x 1.625) = 8.30 sqaure inches

N = 2500 RPM/2 = 1250 powerstrokes/minute

K = 8 cylinders

(195 x 0.25 x 8.30 x 1250 x 8)/33,000 =
122.61 IHP

122.61 INDICATED HORSEPOWER

Now if you wanted to get the Brake Horsepower
out of this application, first you would either
have to find out the work (rotational distance time force applied) per 1 revolution of the flywheel divided into (2 x 3.14159) this would get your the torque. Then from there multiply it back to (2 x 3.14159) times the RPM. Whatever that differs from the Indicated Horsepower Calculation, is the Friction Horsepower losses. IHP - Friction HP = BHP.

This also points to the fact that you need motion or speed involved when figuring out Horsepower. This relates to the Twinkie "Horsepower" question. It would have to be applied to whatever application of 1.68 HP would be. Or 550 foot-lbs/second x 1.68 in terms of time, distance and force exerted within the person who ate that Twinky. So at best the 1.68 HP is just a rough base power rating for the Twinky. How it is expended over time, distance and force exerted is completely abstract.

One last fact regarding Horsepower, is the fact that NO HORSEPOWER exists without a speed or motion of the application being factored into the equation.

A good example of this aside from the previous ones, is turbine jet engines. It is simple to calculate the theoretical Horsepower rating of given Jet Propulsion Engines. But NO HORSEPOWER exists in any Jet Engine, even at peak thrust output UNLESS the aircraft is in MOTION!! So a Static Thrust rating (thrust while aircraft is held at rest) regardless to the amount of thrust is ALWAYS ZERO HORSEPOWER.
Only when the aircraft rolls into motion, does the Static Thrust now change into Net Thrust.
Net Thrust is when the given thrust rating is applied AND the aircraft IS in MOTION! Then Horsepower output is developing.

An example of this, is with the following question:

The Boeing 747-200 airliner has a max net thrust rating of 230,000 lbs. Calculate the mechanical horsepower equivalent of the thrust rating output of the four engines on the B747-200, when it is traveling at 500 MHP.

1 Horsepower = 1 lbs. of thrust AT 375 MHP.

375 MHP = 550 feet per second.

This means that 230,000 lbs. of thrust will have a mechanical horsepower equivalent when traveling at 500 MHP of:

500/375 = 1.33

1.33 x 230,000 = 306,666.67

306,666.67 HP IS THE MECHANICAL EQUIVALENT HORSEPOWER RATING OF THE B747-200 WITH 230,000 LBS. OF THRUST MOVING AT 500 MHP.

THERE NEEDS TO BE SPEED OR MOTION INVOLVED IN ANYTHING FOR WHICH A HORSEPOWER RATING IS TO BE CALCULATED. IN PISTON ENGINES IT INVOLVES RPM. IN JET ENGINES IT INVOLVES FORWARD SPEED. WITH THE TWINKY IT MAY APPLIED TO THE AMOUNT OF FORCE THE PERSON EXERTS A CERTAIN DISTANCE. THE CALORIC HEAT RELEASE OF A 300 CALORIE TWINKY WILL ALLOW THE PERSON TO ACCOMPLISH AN "X" AMOUNT OF FORCE APPLIED TO A "X" AMOUNT OF DISTANCE OVER AN "X" AMOUNT OF TIME.

IN ALL TECHNICAL CHEMISTRY AND PHYSICS TRAINING FOR ANY OF THESE TECHNOLOGY FIELDS, THERE'S ALWAYS A QUESTION WHERE A RUNNER EATS A HAMBURGER WITH A CERTAIN CALORIE COUNT, AND THE STUDENT IS TOLD TO CALCULATE THE THEORETICAL DISTANCE THIS RUNNER COULD ATTAIN, BASED ON HIS/HER WEIGHT (FORCE) AND THE DISTANCE HE/SHE ACCOMPLISHES OVER TIME, TO THAT CONSUMED HAMBURGER. THAT IS THE SAME THING WITH THIS TWINKY.

Good call! I'm just a dumb engineer

Or just capitalize the C in Calorie! Keep up the good work! Don't mind me!

That's why I made sure to specify these as food calories, not simply "calories." The calorie count for an item of food is actually in kilocalories. If a food item has "100 calories," that's 100,000 of the calories you're thinking of.

Probably should have made that clearer.