ADC Value from load cell to MSP430 not correct
What is the gain of the INA125 set to?

It sounds like you need a lot more gain in the instrumentation amplifier. If you don't have a resistor \$R_{G}\$ between the pins 8 and 9 of the instrumentation amplifier, your overall gain of the load-cell output will be only 4.

The load cell you have specced has a 1 mV/V output. Since it sounds like you're feeding the load-cell with your 2.5V reference, this means the full-scale output of the load-cell will be 2.5 mV. With the 4X gain in the INA125, that is 10 mV into the ADC input.

With a 10-bit ADC and 2.5V reference, your bit-size is ~0.0024 v/bit (\$\frac{2.5V}{2^{10}}\$), you should expect a change of \$\frac{0.010V}{0.0024V} \$, or approximately ~4 LSBs, and that's for the maximum load the load-cell is rated for. 

So... Unless you have something else going on that you have not described, it sounds like you're getting significantly more output then would be expected. I would guess you have some gain in the INA125 that you have not described.

The solution here, of course, is to put a voltmeter on the interconnect between the INA125 and the MCU's ADC. That way, you can measure the real voltage going into the MCU, which will tell you where your error is coming from (MCU's ADC, or the INA).