Marko Arnautovic's early goal condemned the Blues to a fourth defeat of the season at the London Stadium and subsequently leaves them 11 points adrift of leaders Manchester City in the fight for the Premier League.
The Blues boss suggested that his players looked tired during the game against the Hammers given that they were playing a second game in five days following the midweek Champions League group draw against Atletico Madrid at Stamford Bridge.
And he now believes their European exertions this term have put paid to any hopes of retaining their title.
Conte said: "This is the fourth defeat in 16 games. When you have these stats it's impossible to think you are in the title race.
"If you want to stay in the race for the title in the first part of the season you can only lose once or twice."
The games continue to come thick and fast for Chelsea with a trip to Huddersfield on Tuesday night and punters may choose to use their free bet to back Conte's men to return to winning ways at the John Smith's Stadium.