Almost all dietary guidelines recommend to restrict calorie intake from sugar. For example NHS website states that your daily free sugar intake should not increase 30 grams which is about 5 percent of your daily calories. 
American Heart Association also recommends that your daily calories from added sugars should not be more than 6 percent and this is about 100 calories (6 teaspoons) for women and 150 calories (9 teaspoons) for men. 
Similarly Dietary Guidelines for the Americans are a big generous and recommend that daily intake of added sugars should not exceed 10 percent. 
Added Sugar is Not Same as Sugar in Fruits
One thing you should note that all these dietary guidelines mention added sugars and not sugar itself. Added sugars are different from normal sugars found in natural sources like fruits.
While there is sugar in fruits and technically it is sugar but there is a difference. The fructose in fruits is within fruit cells and it does not immediately become part of the blood stream. The body has to break down these cells to extract this sugar.
This means that you will remain satiated for a longer period of time and the sugar from fruits will be released slowly into blood stream. Al this means you eating less calories.
In fact there is universal agreement in scientific literature that fruits are good for health and weight loss. These are not associated with diseases. In fact, many research studies have linked more fruit consumption with reduced risks for obesity and many chronic disease because of all the healthy elements like phytochemicals found in fruits.  
In fact one study explicitly found a negative link between eating more fruit and diabetes. 
However, there is one caveat. You can not equate packed fruit juice with fruit because of all the added sugars in processed fruit juice. Even otherwise, when you even drink fresh juice, you break the cells which makes the sugar in juice readily available in your blood stream and all this means you will feel hungrier sooner and eat more calories.
And it also means you will be depriving your body of all the other healthy ingredients of fruits when you do not eat whole fruits.
Do Fruits Make you Gain Weight
If you stick to eating whole fruits and eat high energy fruits like grapes and bananas in moderation, there is infact a lot more chance that you will lose weight by eating fruits. A study published in Internal Journal of Obesity in 2004 found that more fruit and vegetable intake reduces chances of obesity by 24 percent. 
Similarly another study conducted in 2006 also showed the relationship between normal weight and consumption of more fiber based fruits. 
In fact an earlier study published in South African Medical Journal had concluded that eating a lot of fruit, even up to 20 servings a day did neither make the subjects obese nor their insulin and lipid levels were affected adversely. This is the only medical study that states that even eating unlimited amounts of fruit will not make you make fat. 
So do not worry about eating a lot of fruit. It only helps with better health and in many cases with losing weight. The Dietary Guidelines 2015-2020 state that fruit intake is below recommended levels for all age groups.
What is needed is increase in fruit consumption but only fresh and whole fruits and not fruit juice. An more importantly if you keep it a mix of fruits, you can stop worrying about fruit having negative effect on your weight. In fact the agreement about fruits being healthy is so conclusive among health experts that their effects on weight gain are not even on the medical science radar.