Whole fruits are always excellent for your health, whereas fruit juices (such as orange or grapefruit juice) cause significant variations in glucose (blood sugar spikes) compared to very low-sugar options like lemon juice.

noli's read

It is accurate that fruit juices lead to a faster glycemic response than whole fruits. According to data from observational cohort studies (such as the Nurses' Health Study), a whole fruit provides fiber (approximately 3 g for an orange) that slows the assimilation of sugars, whereas its juice is almost devoid of it. Furthermore, a meta-analysis of cohort studies published in JAMA Network Open confirms that daily fruit juice consumption is correlated with a slightly higher metabolic risk than that of whole fruits. However, comparing orange juice to lemon juice is somewhat misleading, as lemon contains almost no natural carbohydrates, which mechanically explains its flat glucose curve. In parallel, meta-analyses of randomized controlled trials (such as that of Murphy et al., 2017) show that 100% pure juice does not alter long-term glycemic balance in healthy individuals. Demonizing temporary glucose variations (the +30 to +60 mg/dL spikes outlined in their charts) in healthy individuals is therefore an exaggeration, as these post-meal fluctuations are part of the normal and healthy functioning of our bodies.

the sources

1. 1Malik VS, Hu FB 2019
2. 2Yang Q, Zhang Z, Gregg EW, et al. 2014
3. 3Westwater ML, Fletcher PC, Ziauddeen H 2016