Eating in Summer with Phoebe Liebling

I don’t know about you but I am a hugely seasonal person.

And when I say this yes I mean I am a huge proponent of eating seasonally, but I also adapt my dietary and lifestyle habits, as I feel and function totally different between summer & winter too. Which when you start to pick apart what the seasonal changes tell our physiology, makes total sense.

Daylight

If we are to be unpoetic, we eat to provide our body with the raw materials to make energy. But this is not only where energy comes from. Our innate daily cycle of when we feel wakeful and when we feel tired is governed by two hormones - cortisol & melatonin - and the efficacy of these is in turn governed by our exposure to natural light. So as a very simple first step in terms of understanding our seasonal variations in food habits we can see a link here.

During the summer the days are much longer, in fact in 2022 there was an 8 hour and 49 minute difference in daylight hours between the December & June solstices (our shortest & longest days of the year). So our circadian rhythm contribution, in terms of our energy levels, is far more impactful on our overall requirement each summer day versus each darker wintry one. When teams at the University of Massachusetts Medical School & the University of Georgia researched this more closely, they found this to correlate with an average fall in energy intake from food during the summer months of ~200kcal per day. We also tend to drink more water unconsciously when it’s warmer and as dehydration is often confused for hunger, this can contribute to a fall in overall calorie intake too.

Temperature

Another key contender in this interesting web, and actually another quite obvious one when we take a minute to think about it, is that of temperature on hunger signalling. Again using myself as an example, because what better guinea pig do I have at my disposal, I know I am definitely hungrier in the winter. If on a summer’s day I find myself more than satisfied by 3 meals, or even 2 meals and a snack if it is really hot, in the winter I will absolutely supplement that framework with additional snacks or things like hot cacao or another almond milky latte situation. And this is because maintaining our body temperature is an energetic process. We need energy in the form of calories from food to stoke those internal fires. We are also balancing out the impact of keeping ourselves wakeful and energetic when it is darker.

I would also highlight that digestion is a heat producing reaction (AKA exothermic), so if we are hot, our appetite decreases as a natural way to help our body cool down. When warm we also tend to digest more slowly which keeps us feeling fuller for longer, thus decreasing our hunger further. If you wanted to, you could measure your body temperature before a meal and then again 20-30 minutes afterwards. You would see an increase of a few degrees, which is a reflection of those internal metabolic reactions occurring.

Exercise

To then switch angles ever so slightly let’s talk about seasonal variations in our exercise habits. I believe that the body remodelling of ‘less energy in + more energy out = decreased fat mass’ is too basic, as this doesn't tell the whole story but also, there is a tendency for us to naturally be leaner in the summer months. This is very much contributed to by the above, but also because naturally we are more motivated to move and be outside in warmer weather. It’s less to do with ‘working out’ more, but that our non-exercise activity thermogenesis increases in the summer. We will walk/cycle to places rather than taking public transport or driving if we can on a sunny day. Evenings are brighter so we might find ourselves out in the garden or going for a stroll after dinner instead of watching TV or doing something more sedentary.

This continuous reminder for our bodies to use energy is compounded by the support of our circadian rhythm by the longer days as this lower stress hormone levels, which means lower insulin levels, which means a body able to utilise stored energy (fat) as fuel. We keep triggering our body to use energy, whilst naturally finding we need to take less in, and hey presto - our bodies evolve without obvious effort.

This is something I am always very keen to highlight to my clients as a critical balance to strike when it comes to the forms of physical activity we choose to do in summer and winter. When our body is supported by all of these elements in summer, we can ask more of it in terms of performance - we can up our cardio basically. Whereas in winter endurance exercise will often (more in women than in men) be a form of additional stress that actually proves to be counter-productive. This is a topic for another day but I’ll just conclude this point by saying that regular movement is always the aim of the game. However, this should be adapted to other burdens your body is facing at that point in the year.

How to eat in summer

Wrapping this all up into a nice neat, edible parcel for you now, I obviously want to finish by relating this all to the foods we choose to eat at different times of year. From all the bits above we can see that during the summer our urges for lighter, cooler foods, fewer of the stodgy style carbohydrates and heavy proteins, in addition to often having smaller portions overall, come from a number of different places. We don’t need or want to produce so much heat as a result of our digestive process, and we don’t need as much in terms of caloric intake.

Therefore, we will veer towards brighter, fresher dishes using all the beautifully vibrant seasonal produce, such as asparagus, fennel, courgette, runner beans & new potatoes with a zesty dressing. We then will usually combine this with a less hearty protein source such as tofu, poultry or fish rather than those things we seek in winter that will create more exothermic energy as we break them down. It’s interesting how if we listen to and live in tandem with nature, it will always give us exactly what we need when we need it….

Discover more of Phoebe's work here.

Try out our Summer Set programme: 10 transformative days of nourishing, vibrant seasonal food and drink, paired with supporting gifts and movement to supercharge into summer this year!