Trying to make hunger bar decrease when I press Left shift. (?)

-- Made script that shrinks a frame as I hold down button.

Why it not work?

local uis = game:GetService("UserInputService")
local shrinking = false
local r = 1/1000 -- gui should shrink by 0.1% on wait() but doesn't 0.001 as a percentage is 0.1%
local gui =  script.Parent -- change this at your discretion

function Shrink()
shrinking = true
while shrinking do
local s = gui.Size
gui.Size = s - UDim2.new(s.X.Scale*r,s.X.Offset*r,s.Y.Scale*r,s.Y.Offset*r)
end
end

uis.InputBegan:connect(function(input,gp)
if input.UserInputType == Enum.UserInputType.Keyboard and gp then
if input.KeyCode == Enum.KeyCode.LeftShift then
Shrink()
end
end
end)

uis.InputEnded:connect(function(input,gp)
if input.UserInputType == Enum.UserInputType.Keyboard and gp then
if input.KeyCode == Enum.KeyCode.LeftShift then
shrinking = false
end
end
end)

Here is the problem:

uis.InputBegan:connect(function(input,gp)
	if input.UserInputType == Enum.UserInputType.Keyboard and gp then

"gp" is a bool that stands for Game Processed Event, which is only true when the input happened upon an interface. You most likely DON'T want this, because then your function only works when you type into chat. Therefore you should say "and (not gp)" at the end of both functions.

Fixed:

uis.InputBegan:connect(function(input,gp)
	if input.UserInputType == Enum.UserInputType.Keyboard and (not gp) then