When using ISO to fine tune exposure there are a few things you should realize about how Canon DSLRs work with regard to +1/3 and -1/3 stop ISO settings.

The sensor in your EOS 7D Mark II has a base ISO of 100.

The amplification of the sensor is only increased for "full" stop ISO settings. That is, ISO 200, 400, 800, 1600, and so on.

For the -1/3 stop settings (ISO 160, 320, 640, 1250, etc.) the sensor is amplified for the full stop setting just above it (ISO 200, 400, 800, 1600, etc.) with instructions in the raw file to "pull" the exposure 1/3 stop when converting the raw file. This has the same effect as "Exposing to the Right" 1/3 stop with regard to the signal-to-noise ratio.

For the +1/3 stop settings (ISO 125, 250, 500, 1000, 2000, etc.) the sensor is set at the full stop just below it (ISO 100, 200, 400, 800, 1600, etc.) with instructions in the raw file to "push" the exposure 1/3 stop when converting the raw file. This has the same effect as underexposing by 1/3 stop with regard to the signal-to-noise ratio.

Both the "pushing" and "pulling" reduce the camera's total dynamic range by 1/3 stop. "Pulling" the -1/3 stop settings also reduce the noise in the shadows by 1/3 stop. "Pushing" the +1/3 stops, on the other hand, also "push" shadow noise by 1/3 stop. In some tests of Canon EOS models ISO 125 has been shown to be noisier than ISO 800 and just as noisy in the shadows as ISO 1250! How this works out practically and links to some of those tests are covered in Is it really better to shoot at full-stop ISOs?

Your EOS 7D Mark II includes menu options that allow only using the full stop ISO settings or that allow using all of the 1/3 stop ISO settings as well. If you decide to continue to use ISO to adjust the exposure for a specific shutter time (Tv) and aperture (Av), I would recommend setting the ISO speed setting increments under Custom Function (Orange) Tab 1 to 1/1: 1-stop to avoid the +1/3 stop settings (ISO 125, 250, 500, 1000, etc.) that increase the noise and reduce the signal to noise ratio. Understand that this will mean each click of the control wheel when changing ISO is one full stop, rather than the default three clicks per stop when 1/3: 1/3-stop is selected at the menu option mentioned above.

When you initiate metering you'll need to take note of how far above or below "0" the camera indicates your current settings are. You should then adjust the ISO to get as close to "0" as possible and then fine tune the exposure with the 1/3 stop settings for Tv and/or Av.

Another thing the EOS 7D Mark II allows that you may not be familiar with is the option to select Auto ISO when in Manual exposure mode. When you initiate metering the display will change from showing an "A" (for Auto) to the ISO setting the metering system has selected to match your already set Tv and Av. You can set the minimum and maximum allowable ISO settings when using Auto ISO under the Shooting (Red) Tab 2 menu.