It has become Nintendo's second best chart-topper - Pokemon Gold also made it to No.1 a total of seven times in 2001. Wii Fit needs to hit the top spot another four times to beat the Nintendo game which has been number one the most; Pokemon Yellow spent 10 weeks at the top in 2000.
Although the Nintendo game is the UK No.1, it has actually seen a decline in sales by 17 per cent according to ChartTrack data.
However the second-biggest game of the week also saw a similar decline, presumably as the post-Christmas spending on Q4 titles dwindles ahead of the ramp up of new releases due out in February and March; Activision Blizzard's Call of Duty: World at War remains at No.2 despite a fall of 11 per cent.
Elswhere, EA's FIFA climbs at place to No.3, with sales up 9 per cent, while Nintendo's other 'super franchise in the making' Professor Layton also climbs the chart to No.4, with sales up a huge 54 per cent as a wave of new stock for the much-wanted DS title hit stores.
Skate 2 falls two spots down to No5 (down 28 per cent), while Nintendo takes No.6 and No.7 with Mario Kart Wii (up five percent) and Wii Play (down 19 per cent).
Ubisoft's My Fitness Coach also goes down a place to No.8, with Tomb Raider Underworld holding firm at No.9 and EA's Need For Speed: Undercover up three places to No.10.
New releases haven't made it into the All Formats Top 40, but ChartTrack points out that EA’s new SimAnimals title did debut No.16 in the Wii Full Price chart and No.20 in the DS Full Price chart, while on the PC Full Price chart Ubisoft's new CSI: New York hit No.6 while THQ's Saints Row 2 debuted at No.18.
The top 10 for the week ending February 1st is as follows:
1. Wii Fit (Nintendo)
2. Call of Duty: World at War (Activision Blizzard)
3. FIFA 09 (EA)
4. Professor Layton and the Curious Village (Nintendo)
5. Skate 2 (EA)
6. Mario Kart Wii (Nintendo)
7. Wii Play (Nintendo)
8. My Fitness Coach (Ubisoft)
9. Tomb Raider: Underworld (Eidos)
10. Need for Speed: Undercover (EA)